1 /*
2 * Copyright (c) 1997, 2020, Oracle and/or its affiliates. All rights reserved.
3 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
4 *
5 * This code is free software; you can redistribute it and/or modify it
6 * under the terms of the GNU General Public License version 2 only, as
7 * published by the Free Software Foundation.
8 *
9 * This code is distributed in the hope that it will be useful, but WITHOUT
10 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
11 * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
12 * version 2 for more details (a copy is included in the LICENSE file that
13 * accompanied this code).
14 *
15 * You should have received a copy of the GNU General Public License version
16 * 2 along with this work; if not, write to the Free Software Foundation,
17 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
18 *
19 * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
20 * or visit www.oracle.com if you need additional information or have any
21 * questions.
22 *
23 */
24
25 #include "precompiled.hpp"
26 #include "jvm.h"
27 #include "aot/aotLoader.hpp"
28 #include "classfile/classFileParser.hpp"
29 #include "classfile/classFileStream.hpp"
30 #include "classfile/classLoader.hpp"
31 #include "classfile/classLoaderData.inline.hpp"
32 #include "classfile/javaClasses.hpp"
33 #include "classfile/moduleEntry.hpp"
34 #include "classfile/resolutionErrors.hpp"
35 #include "classfile/symbolTable.hpp"
36 #include "classfile/systemDictionary.hpp"
37 #include "classfile/systemDictionaryShared.hpp"
38 #include "classfile/verifier.hpp"
39 #include "classfile/vmSymbols.hpp"
40 #include "code/dependencyContext.hpp"
41 #include "compiler/compileBroker.hpp"
42 #include "gc/shared/collectedHeap.inline.hpp"
43 #include "interpreter/oopMapCache.hpp"
44 #include "interpreter/rewriter.hpp"
45 #include "jvmtifiles/jvmti.h"
46 #include "logging/log.hpp"
47 #include "logging/logMessage.hpp"
48 #include "logging/logStream.hpp"
49 #include "memory/allocation.inline.hpp"
50 #include "memory/iterator.inline.hpp"
51 #include "memory/metadataFactory.hpp"
52 #include "memory/metaspaceClosure.hpp"
53 #include "memory/metaspaceShared.hpp"
54 #include "memory/oopFactory.hpp"
55 #include "memory/resourceArea.hpp"
56 #include "memory/universe.hpp"
57 #include "oops/fieldStreams.inline.hpp"
58 #include "oops/constantPool.hpp"
59 #include "oops/instanceClassLoaderKlass.hpp"
60 #include "oops/instanceKlass.inline.hpp"
61 #include "oops/instanceMirrorKlass.hpp"
62 #include "oops/instanceOop.hpp"
63 #include "oops/klass.inline.hpp"
64 #include "oops/method.hpp"
65 #include "oops/oop.inline.hpp"
66 #include "oops/recordComponent.hpp"
67 #include "oops/symbol.hpp"
68 #include "prims/jvmtiExport.hpp"
69 #include "prims/jvmtiRedefineClasses.hpp"
70 #include "prims/jvmtiThreadState.hpp"
71 #include "prims/methodComparator.hpp"
72 #include "runtime/atomic.hpp"
73 #include "runtime/biasedLocking.hpp"
74 #include "runtime/fieldDescriptor.inline.hpp"
75 #include "runtime/handles.inline.hpp"
76 #include "runtime/javaCalls.hpp"
77 #include "runtime/mutexLocker.hpp"
78 #include "runtime/orderAccess.hpp"
79 #include "runtime/thread.inline.hpp"
80 #include "services/classLoadingService.hpp"
81 #include "services/threadService.hpp"
82 #include "utilities/dtrace.hpp"
83 #include "utilities/events.hpp"
84 #include "utilities/macros.hpp"
85 #include "utilities/stringUtils.hpp"
86 #ifdef COMPILER1
87 #include "c1/c1_Compiler.hpp"
88 #endif
89 #if INCLUDE_JFR
90 #include "jfr/jfrEvents.hpp"
91 #endif
92
93
94 #ifdef DTRACE_ENABLED
95
96
97 #define HOTSPOT_CLASS_INITIALIZATION_required HOTSPOT_CLASS_INITIALIZATION_REQUIRED
98 #define HOTSPOT_CLASS_INITIALIZATION_recursive HOTSPOT_CLASS_INITIALIZATION_RECURSIVE
99 #define HOTSPOT_CLASS_INITIALIZATION_concurrent HOTSPOT_CLASS_INITIALIZATION_CONCURRENT
100 #define HOTSPOT_CLASS_INITIALIZATION_erroneous HOTSPOT_CLASS_INITIALIZATION_ERRONEOUS
101 #define HOTSPOT_CLASS_INITIALIZATION_super__failed HOTSPOT_CLASS_INITIALIZATION_SUPER_FAILED
102 #define HOTSPOT_CLASS_INITIALIZATION_clinit HOTSPOT_CLASS_INITIALIZATION_CLINIT
103 #define HOTSPOT_CLASS_INITIALIZATION_error HOTSPOT_CLASS_INITIALIZATION_ERROR
104 #define HOTSPOT_CLASS_INITIALIZATION_end HOTSPOT_CLASS_INITIALIZATION_END
105 #define DTRACE_CLASSINIT_PROBE(type, thread_type) \
106 { \
107 char* data = NULL; \
108 int len = 0; \
109 Symbol* clss_name = name(); \
110 if (clss_name != NULL) { \
111 data = (char*)clss_name->bytes(); \
112 len = clss_name->utf8_length(); \
113 } \
114 HOTSPOT_CLASS_INITIALIZATION_##type( \
115 data, len, (void*)class_loader(), thread_type); \
116 }
117
118 #define DTRACE_CLASSINIT_PROBE_WAIT(type, thread_type, wait) \
119 { \
120 char* data = NULL; \
121 int len = 0; \
122 Symbol* clss_name = name(); \
123 if (clss_name != NULL) { \
124 data = (char*)clss_name->bytes(); \
125 len = clss_name->utf8_length(); \
126 } \
127 HOTSPOT_CLASS_INITIALIZATION_##type( \
128 data, len, (void*)class_loader(), thread_type, wait); \
129 }
130
131 #else // ndef DTRACE_ENABLED
132
133 #define DTRACE_CLASSINIT_PROBE(type, thread_type)
134 #define DTRACE_CLASSINIT_PROBE_WAIT(type, thread_type, wait)
135
136 #endif // ndef DTRACE_ENABLED
137
138
139 static inline bool is_class_loader(const Symbol* class_name,
140 const ClassFileParser& parser) {
141 assert(class_name != NULL, "invariant");
142
143 if (class_name == vmSymbols::java_lang_ClassLoader()) {
144 return true;
145 }
146
147 if (SystemDictionary::ClassLoader_klass_loaded()) {
148 const Klass* const super_klass = parser.super_klass();
149 if (super_klass != NULL) {
150 if (super_klass->is_subtype_of(SystemDictionary::ClassLoader_klass())) {
151 return true;
152 }
153 }
154 }
155 return false;
156 }
157
158 // private: called to verify that k is a static member of this nest.
159 // We know that k is an instance class in the same package and hence the
160 // same classloader.
161 bool InstanceKlass::has_nest_member(InstanceKlass* k, TRAPS) const {
162 assert(!is_hidden(), "unexpected hidden class");
163 if (_nest_members == NULL || _nest_members == Universe::the_empty_short_array()) {
164 if (log_is_enabled(Trace, class, nestmates)) {
165 ResourceMark rm(THREAD);
166 log_trace(class, nestmates)("Checked nest membership of %s in non-nest-host class %s",
167 k->external_name(), this->external_name());
168 }
169 return false;
170 }
171
172 if (log_is_enabled(Trace, class, nestmates)) {
173 ResourceMark rm(THREAD);
174 log_trace(class, nestmates)("Checking nest membership of %s in %s",
175 k->external_name(), this->external_name());
176 }
177
178 // Check for a resolved cp entry , else fall back to a name check.
179 // We don't want to resolve any class other than the one being checked.
180 for (int i = 0; i < _nest_members->length(); i++) {
181 int cp_index = _nest_members->at(i);
182 if (_constants->tag_at(cp_index).is_klass()) {
183 Klass* k2 = _constants->klass_at(cp_index, THREAD);
184 assert(!HAS_PENDING_EXCEPTION || PENDING_EXCEPTION->is_a(SystemDictionary::VirtualMachineError_klass()),
185 "Exceptions should not be possible here");
186 if (k2 == k) {
187 log_trace(class, nestmates)("- class is listed at nest_members[%d] => cp[%d]", i, cp_index);
188 return true;
189 }
190 }
191 else {
192 Symbol* name = _constants->klass_name_at(cp_index);
193 if (name == k->name()) {
194 log_trace(class, nestmates)("- Found it at nest_members[%d] => cp[%d]", i, cp_index);
195
196 // Names match so check actual klass. This may trigger class loading if
197 // it doesn't match though that should be impossible as it means one classloader
198 // has defined two different classes with the same name! A compiler thread won't be
199 // able to perform that loading but we can't exclude the compiler threads from
200 // executing this logic. But it should actually be impossible to trigger loading here.
201 Klass* k2 = _constants->klass_at(cp_index, THREAD);
202 assert(!HAS_PENDING_EXCEPTION || PENDING_EXCEPTION->is_a(SystemDictionary::VirtualMachineError_klass()),
203 "Exceptions should not be possible here");
204 if (k2 == k) {
205 log_trace(class, nestmates)("- class is listed as a nest member");
206 return true;
207 }
208 else {
209 // same name but different klass!
210 log_trace(class, nestmates)(" - klass comparison failed!");
211 // can't have two names the same, so we're done
212 return false;
213 }
214 }
215 }
216 }
217 log_trace(class, nestmates)("- class is NOT a nest member!");
218 return false;
219 }
220
221 // Return nest-host class, resolving, validating and saving it if needed.
222 // In cases where this is called from a thread that cannot do classloading
223 // (such as a native JIT thread) then we simply return NULL, which in turn
224 // causes the access check to return false. Such code will retry the access
225 // from a more suitable environment later. Otherwise the _nest_host is always
226 // set once this method returns.
227 // Any errors from nest-host resolution must be preserved so they can be queried
228 // from higher-level access checking code, and reported as part of access checking
229 // exceptions.
230 // VirtualMachineErrors are propagated with a NULL return.
231 // Under any conditions where the _nest_host can be set to non-NULL the resulting
232 // value of it and, if applicable, the nest host resolution/validation error,
233 // are idempotent.
234 InstanceKlass* InstanceKlass::nest_host(TRAPS) {
235 InstanceKlass* nest_host_k = _nest_host;
236 if (nest_host_k != NULL) {
237 return nest_host_k;
238 }
239
240 ResourceMark rm(THREAD);
241
242 // need to resolve and save our nest-host class.
243 if (_nest_host_index != 0) { // we have a real nest_host
244 // Before trying to resolve check if we're in a suitable context
245 if (!THREAD->can_call_java() && !_constants->tag_at(_nest_host_index).is_klass()) {
246 log_trace(class, nestmates)("Rejected resolution of nest-host of %s in unsuitable thread",
247 this->external_name());
248 return NULL; // sentinel to say "try again from a different context"
249 }
250
251 log_trace(class, nestmates)("Resolving nest-host of %s using cp entry for %s",
252 this->external_name(),
253 _constants->klass_name_at(_nest_host_index)->as_C_string());
254
255 Klass* k = _constants->klass_at(_nest_host_index, THREAD);
256 if (HAS_PENDING_EXCEPTION) {
257 if (PENDING_EXCEPTION->is_a(SystemDictionary::VirtualMachineError_klass())) {
258 return NULL; // propagate VMEs
259 }
260 stringStream ss;
261 char* target_host_class = _constants->klass_name_at(_nest_host_index)->as_C_string();
262 ss.print("Nest host resolution of %s with host %s failed: ",
263 this->external_name(), target_host_class);
264 java_lang_Throwable::print(PENDING_EXCEPTION, &ss);
265 const char* msg = ss.as_string(true /* on C-heap */);
266 constantPoolHandle cph(THREAD, constants());
267 SystemDictionary::add_nest_host_error(cph, _nest_host_index, msg);
268 CLEAR_PENDING_EXCEPTION;
269
270 log_trace(class, nestmates)("%s", msg);
271 } else {
272 // A valid nest-host is an instance class in the current package that lists this
273 // class as a nest member. If any of these conditions are not met the class is
274 // its own nest-host.
275 const char* error = NULL;
276
277 // JVMS 5.4.4 indicates package check comes first
278 if (is_same_class_package(k)) {
279 // Now check actual membership. We can't be a member if our "host" is
280 // not an instance class.
281 if (k->is_instance_klass()) {
282 nest_host_k = InstanceKlass::cast(k);
283 bool is_member = nest_host_k->has_nest_member(this, THREAD);
284 // exception is rare, perhaps impossible
285 if (!HAS_PENDING_EXCEPTION) {
286 if (is_member) {
287 _nest_host = nest_host_k; // save resolved nest-host value
288
289 log_trace(class, nestmates)("Resolved nest-host of %s to %s",
290 this->external_name(), k->external_name());
291 return nest_host_k;
292 } else {
293 error = "current type is not listed as a nest member";
294 }
295 } else {
296 if (PENDING_EXCEPTION->is_a(SystemDictionary::VirtualMachineError_klass())) {
297 return NULL; // propagate VMEs
298 }
299 stringStream ss;
300 ss.print("exception on member check: ");
301 java_lang_Throwable::print(PENDING_EXCEPTION, &ss);
302 error = ss.as_string();
303 }
304 } else {
305 error = "host is not an instance class";
306 }
307 } else {
308 error = "types are in different packages";
309 }
310
311 // something went wrong, so record what and log it
312 {
313 stringStream ss;
314 ss.print("Type %s (loader: %s) is not a nest member of type %s (loader: %s): %s",
315 this->external_name(),
316 this->class_loader_data()->loader_name_and_id(),
317 k->external_name(),
318 k->class_loader_data()->loader_name_and_id(),
319 error);
320 const char* msg = ss.as_string(true /* on C-heap */);
321 constantPoolHandle cph(THREAD, constants());
322 SystemDictionary::add_nest_host_error(cph, _nest_host_index, msg);
323 log_trace(class, nestmates)("%s", msg);
324 }
325 }
326 } else {
327 log_trace(class, nestmates)("Type %s is not part of a nest: setting nest-host to self",
328 this->external_name());
329 }
330
331 // Either not in an explicit nest, or else an error occurred, so
332 // the nest-host is set to `this`. Any thread that sees this assignment
333 // will also see any setting of nest_host_error(), if applicable.
334 return (_nest_host = this);
335 }
336
337 // Dynamic nest member support: set this class's nest host to the given class.
338 // This occurs as part of the class definition, as soon as the instanceKlass
339 // has been created and doesn't require further resolution. The code:
340 // lookup().defineHiddenClass(bytes_for_X, NESTMATE);
341 // results in:
342 // class_of_X.set_nest_host(lookup().lookupClass().getNestHost())
343 // If it has an explicit _nest_host_index or _nest_members, these will be ignored.
344 // We also know the "host" is a valid nest-host in the same package so we can
345 // assert some of those facts.
346 void InstanceKlass::set_nest_host(InstanceKlass* host, TRAPS) {
347 assert(is_hidden(), "must be a hidden class");
348 assert(host != NULL, "NULL nest host specified");
349 assert(_nest_host == NULL, "current class has resolved nest-host");
350 assert(nest_host_error(THREAD) == NULL, "unexpected nest host resolution error exists: %s",
351 nest_host_error(THREAD));
352 assert((host->_nest_host == NULL && host->_nest_host_index == 0) ||
353 (host->_nest_host == host), "proposed host is not a valid nest-host");
354 // Can't assert this as package is not set yet:
355 // assert(is_same_class_package(host), "proposed host is in wrong package");
356
357 if (log_is_enabled(Trace, class, nestmates)) {
358 ResourceMark rm(THREAD);
359 const char* msg = "";
360 // a hidden class does not expect a statically defined nest-host
361 if (_nest_host_index > 0) {
362 msg = "(the NestHost attribute in the current class is ignored)";
363 } else if (_nest_members != NULL && _nest_members != Universe::the_empty_short_array()) {
364 msg = "(the NestMembers attribute in the current class is ignored)";
365 }
366 log_trace(class, nestmates)("Injected type %s into the nest of %s %s",
367 this->external_name(),
368 host->external_name(),
369 msg);
370 }
371 // set dynamic nest host
372 _nest_host = host;
373 // Record dependency to keep nest host from being unloaded before this class.
374 ClassLoaderData* this_key = class_loader_data();
375 this_key->record_dependency(host);
376 }
377
378 // check if 'this' and k are nestmates (same nest_host), or k is our nest_host,
379 // or we are k's nest_host - all of which is covered by comparing the two
380 // resolved_nest_hosts.
381 // Any exceptions (i.e. VMEs) are propagated.
382 bool InstanceKlass::has_nestmate_access_to(InstanceKlass* k, TRAPS) {
383
384 assert(this != k, "this should be handled by higher-level code");
385
386 // Per JVMS 5.4.4 we first resolve and validate the current class, then
387 // the target class k.
388
389 InstanceKlass* cur_host = nest_host(CHECK_false);
390 if (cur_host == NULL) {
391 return false;
392 }
393
394 Klass* k_nest_host = k->nest_host(CHECK_false);
395 if (k_nest_host == NULL) {
396 return false;
397 }
398
399 bool access = (cur_host == k_nest_host);
400
401 ResourceMark rm(THREAD);
402 log_trace(class, nestmates)("Class %s does %shave nestmate access to %s",
403 this->external_name(),
404 access ? "" : "NOT ",
405 k->external_name());
406 return access;
407 }
408
409 const char* InstanceKlass::nest_host_error(TRAPS) {
410 if (_nest_host_index == 0) {
411 return NULL;
412 } else {
413 constantPoolHandle cph(THREAD, constants());
414 return SystemDictionary::find_nest_host_error(cph, (int)_nest_host_index);
415 }
416 }
417
418 InstanceKlass* InstanceKlass::allocate_instance_klass(const ClassFileParser& parser, TRAPS) {
419 bool is_hidden_or_anonymous = parser.is_hidden() || parser.is_unsafe_anonymous();
420 const int size = InstanceKlass::size(parser.vtable_size(),
421 parser.itable_size(),
422 nonstatic_oop_map_size(parser.total_oop_map_count()),
423 parser.is_interface(),
424 parser.is_unsafe_anonymous(),
425 should_store_fingerprint(is_hidden_or_anonymous));
426
427 const Symbol* const class_name = parser.class_name();
428 assert(class_name != NULL, "invariant");
429 ClassLoaderData* loader_data = parser.loader_data();
430 assert(loader_data != NULL, "invariant");
431
432 InstanceKlass* ik;
433
434 // Allocation
435 if (REF_NONE == parser.reference_type()) {
436 if (class_name == vmSymbols::java_lang_Class()) {
437 // mirror
438 ik = new (loader_data, size, THREAD) InstanceMirrorKlass(parser);
439 }
440 else if (is_class_loader(class_name, parser)) {
441 // class loader
442 ik = new (loader_data, size, THREAD) InstanceClassLoaderKlass(parser);
443 } else {
444 // normal
445 ik = new (loader_data, size, THREAD) InstanceKlass(parser, InstanceKlass::_misc_kind_other);
446 }
447 } else {
448 // reference
449 ik = new (loader_data, size, THREAD) InstanceRefKlass(parser);
450 }
451
452 // Check for pending exception before adding to the loader data and incrementing
453 // class count. Can get OOM here.
454 if (HAS_PENDING_EXCEPTION) {
455 return NULL;
456 }
457
458 return ik;
459 }
460
461
462 // copy method ordering from resource area to Metaspace
463 void InstanceKlass::copy_method_ordering(const intArray* m, TRAPS) {
464 if (m != NULL) {
465 // allocate a new array and copy contents (memcpy?)
466 _method_ordering = MetadataFactory::new_array<int>(class_loader_data(), m->length(), CHECK);
467 for (int i = 0; i < m->length(); i++) {
468 _method_ordering->at_put(i, m->at(i));
469 }
470 } else {
471 _method_ordering = Universe::the_empty_int_array();
472 }
473 }
474
475 // create a new array of vtable_indices for default methods
476 Array<int>* InstanceKlass::create_new_default_vtable_indices(int len, TRAPS) {
477 Array<int>* vtable_indices = MetadataFactory::new_array<int>(class_loader_data(), len, CHECK_NULL);
478 assert(default_vtable_indices() == NULL, "only create once");
479 set_default_vtable_indices(vtable_indices);
480 return vtable_indices;
481 }
482
483 InstanceKlass::InstanceKlass(const ClassFileParser& parser, unsigned kind, KlassID id) :
484 Klass(id),
485 _nest_members(NULL),
486 _nest_host_index(0),
487 _nest_host(NULL),
488 _record_components(NULL),
489 _static_field_size(parser.static_field_size()),
490 _nonstatic_oop_map_size(nonstatic_oop_map_size(parser.total_oop_map_count())),
491 _itable_len(parser.itable_size()),
492 _init_thread(NULL),
493 _init_state(allocated),
494 _reference_type(parser.reference_type())
495 {
496 set_vtable_length(parser.vtable_size());
497 set_kind(kind);
498 set_access_flags(parser.access_flags());
499 if (parser.is_hidden()) set_is_hidden();
500 set_is_unsafe_anonymous(parser.is_unsafe_anonymous());
501 set_layout_helper(Klass::instance_layout_helper(parser.layout_size(),
502 false));
503
504 assert(NULL == _methods, "underlying memory not zeroed?");
505 assert(is_instance_klass(), "is layout incorrect?");
506 assert(size_helper() == parser.layout_size(), "incorrect size_helper?");
507
508 if (Arguments::is_dumping_archive()) {
509 SystemDictionaryShared::init_dumptime_info(this);
510 }
511
512 // Set biased locking bit for all instances of this class; it will be
513 // cleared if revocation occurs too often for this type
514 if (UseBiasedLocking && BiasedLocking::enabled()) {
515 set_prototype_header(markWord::biased_locking_prototype());
516 }
517 }
518
519 void InstanceKlass::deallocate_methods(ClassLoaderData* loader_data,
520 Array<Method*>* methods) {
521 if (methods != NULL && methods != Universe::the_empty_method_array() &&
522 !methods->is_shared()) {
523 for (int i = 0; i < methods->length(); i++) {
524 Method* method = methods->at(i);
525 if (method == NULL) continue; // maybe null if error processing
526 // Only want to delete methods that are not executing for RedefineClasses.
527 // The previous version will point to them so they're not totally dangling
528 assert (!method->on_stack(), "shouldn't be called with methods on stack");
529 MetadataFactory::free_metadata(loader_data, method);
530 }
531 MetadataFactory::free_array<Method*>(loader_data, methods);
532 }
533 }
534
535 void InstanceKlass::deallocate_interfaces(ClassLoaderData* loader_data,
536 const Klass* super_klass,
537 Array<InstanceKlass*>* local_interfaces,
538 Array<InstanceKlass*>* transitive_interfaces) {
539 // Only deallocate transitive interfaces if not empty, same as super class
540 // or same as local interfaces. See code in parseClassFile.
541 Array<InstanceKlass*>* ti = transitive_interfaces;
542 if (ti != Universe::the_empty_instance_klass_array() && ti != local_interfaces) {
543 // check that the interfaces don't come from super class
544 Array<InstanceKlass*>* sti = (super_klass == NULL) ? NULL :
545 InstanceKlass::cast(super_klass)->transitive_interfaces();
546 if (ti != sti && ti != NULL && !ti->is_shared()) {
547 MetadataFactory::free_array<InstanceKlass*>(loader_data, ti);
548 }
549 }
550
551 // local interfaces can be empty
552 if (local_interfaces != Universe::the_empty_instance_klass_array() &&
553 local_interfaces != NULL && !local_interfaces->is_shared()) {
554 MetadataFactory::free_array<InstanceKlass*>(loader_data, local_interfaces);
555 }
556 }
557
558 void InstanceKlass::deallocate_record_components(ClassLoaderData* loader_data,
559 Array<RecordComponent*>* record_components) {
560 if (record_components != NULL && !record_components->is_shared()) {
561 for (int i = 0; i < record_components->length(); i++) {
562 RecordComponent* record_component = record_components->at(i);
563 MetadataFactory::free_metadata(loader_data, record_component);
564 }
565 MetadataFactory::free_array<RecordComponent*>(loader_data, record_components);
566 }
567 }
568
569 // This function deallocates the metadata and C heap pointers that the
570 // InstanceKlass points to.
571 void InstanceKlass::deallocate_contents(ClassLoaderData* loader_data) {
572
573 // Orphan the mirror first, CMS thinks it's still live.
574 if (java_mirror() != NULL) {
575 java_lang_Class::set_klass(java_mirror(), NULL);
576 }
577
578 // Also remove mirror from handles
579 loader_data->remove_handle(_java_mirror);
580
581 // Need to take this class off the class loader data list.
582 loader_data->remove_class(this);
583
584 // The array_klass for this class is created later, after error handling.
585 // For class redefinition, we keep the original class so this scratch class
586 // doesn't have an array class. Either way, assert that there is nothing
587 // to deallocate.
588 assert(array_klasses() == NULL, "array classes shouldn't be created for this class yet");
589
590 // Release C heap allocated data that this might point to, which includes
591 // reference counting symbol names.
592 release_C_heap_structures();
593
594 deallocate_methods(loader_data, methods());
595 set_methods(NULL);
596
597 deallocate_record_components(loader_data, record_components());
598 set_record_components(NULL);
599
600 if (method_ordering() != NULL &&
601 method_ordering() != Universe::the_empty_int_array() &&
602 !method_ordering()->is_shared()) {
603 MetadataFactory::free_array<int>(loader_data, method_ordering());
604 }
605 set_method_ordering(NULL);
606
607 // default methods can be empty
608 if (default_methods() != NULL &&
609 default_methods() != Universe::the_empty_method_array() &&
610 !default_methods()->is_shared()) {
611 MetadataFactory::free_array<Method*>(loader_data, default_methods());
612 }
613 // Do NOT deallocate the default methods, they are owned by superinterfaces.
614 set_default_methods(NULL);
615
616 // default methods vtable indices can be empty
617 if (default_vtable_indices() != NULL &&
618 !default_vtable_indices()->is_shared()) {
619 MetadataFactory::free_array<int>(loader_data, default_vtable_indices());
620 }
621 set_default_vtable_indices(NULL);
622
623
624 // This array is in Klass, but remove it with the InstanceKlass since
625 // this place would be the only caller and it can share memory with transitive
626 // interfaces.
627 if (secondary_supers() != NULL &&
628 secondary_supers() != Universe::the_empty_klass_array() &&
629 // see comments in compute_secondary_supers about the following cast
630 (address)(secondary_supers()) != (address)(transitive_interfaces()) &&
631 !secondary_supers()->is_shared()) {
632 MetadataFactory::free_array<Klass*>(loader_data, secondary_supers());
633 }
634 set_secondary_supers(NULL);
635
636 deallocate_interfaces(loader_data, super(), local_interfaces(), transitive_interfaces());
637 set_transitive_interfaces(NULL);
638 set_local_interfaces(NULL);
639
640 if (fields() != NULL && !fields()->is_shared()) {
641 MetadataFactory::free_array<jushort>(loader_data, fields());
642 }
643 set_fields(NULL, 0);
644
645 // If a method from a redefined class is using this constant pool, don't
646 // delete it, yet. The new class's previous version will point to this.
647 if (constants() != NULL) {
648 assert (!constants()->on_stack(), "shouldn't be called if anything is onstack");
649 if (!constants()->is_shared()) {
650 MetadataFactory::free_metadata(loader_data, constants());
651 }
652 // Delete any cached resolution errors for the constant pool
653 SystemDictionary::delete_resolution_error(constants());
654
655 set_constants(NULL);
656 }
657
658 if (inner_classes() != NULL &&
659 inner_classes() != Universe::the_empty_short_array() &&
660 !inner_classes()->is_shared()) {
661 MetadataFactory::free_array<jushort>(loader_data, inner_classes());
662 }
663 set_inner_classes(NULL);
664
665 if (nest_members() != NULL &&
666 nest_members() != Universe::the_empty_short_array() &&
667 !nest_members()->is_shared()) {
668 MetadataFactory::free_array<jushort>(loader_data, nest_members());
669 }
670 set_nest_members(NULL);
671
672 // We should deallocate the Annotations instance if it's not in shared spaces.
673 if (annotations() != NULL && !annotations()->is_shared()) {
674 MetadataFactory::free_metadata(loader_data, annotations());
675 }
676 set_annotations(NULL);
677
678 if (Arguments::is_dumping_archive()) {
679 SystemDictionaryShared::remove_dumptime_info(this);
680 }
681 }
682
683 bool InstanceKlass::should_be_initialized() const {
684 return !is_initialized();
685 }
686
687 klassItable InstanceKlass::itable() const {
688 return klassItable(const_cast<InstanceKlass*>(this));
689 }
690
691 void InstanceKlass::eager_initialize(Thread *thread) {
692 if (!EagerInitialization) return;
693
694 if (this->is_not_initialized()) {
695 // abort if the the class has a class initializer
696 if (this->class_initializer() != NULL) return;
697
698 // abort if it is java.lang.Object (initialization is handled in genesis)
699 Klass* super_klass = super();
700 if (super_klass == NULL) return;
701
702 // abort if the super class should be initialized
703 if (!InstanceKlass::cast(super_klass)->is_initialized()) return;
704
705 // call body to expose the this pointer
706 eager_initialize_impl();
707 }
708 }
709
710 // JVMTI spec thinks there are signers and protection domain in the
711 // instanceKlass. These accessors pretend these fields are there.
712 // The hprof specification also thinks these fields are in InstanceKlass.
713 oop InstanceKlass::protection_domain() const {
714 // return the protection_domain from the mirror
715 return java_lang_Class::protection_domain(java_mirror());
716 }
717
718 // To remove these from requires an incompatible change and CCC request.
719 objArrayOop InstanceKlass::signers() const {
720 // return the signers from the mirror
721 return java_lang_Class::signers(java_mirror());
722 }
723
724 oop InstanceKlass::init_lock() const {
725 // return the init lock from the mirror
726 oop lock = java_lang_Class::init_lock(java_mirror());
727 // Prevent reordering with any access of initialization state
728 OrderAccess::loadload();
729 assert((oop)lock != NULL || !is_not_initialized(), // initialized or in_error state
730 "only fully initialized state can have a null lock");
731 return lock;
732 }
733
734 // Set the initialization lock to null so the object can be GC'ed. Any racing
735 // threads to get this lock will see a null lock and will not lock.
736 // That's okay because they all check for initialized state after getting
737 // the lock and return.
738 void InstanceKlass::fence_and_clear_init_lock() {
739 // make sure previous stores are all done, notably the init_state.
740 OrderAccess::storestore();
741 java_lang_Class::set_init_lock(java_mirror(), NULL);
742 assert(!is_not_initialized(), "class must be initialized now");
743 }
744
745 void InstanceKlass::eager_initialize_impl() {
746 EXCEPTION_MARK;
747 HandleMark hm(THREAD);
748 Handle h_init_lock(THREAD, init_lock());
749 ObjectLocker ol(h_init_lock, THREAD, h_init_lock() != NULL);
750
751 // abort if someone beat us to the initialization
752 if (!is_not_initialized()) return; // note: not equivalent to is_initialized()
753
754 ClassState old_state = init_state();
755 link_class_impl(THREAD);
756 if (HAS_PENDING_EXCEPTION) {
757 CLEAR_PENDING_EXCEPTION;
758 // Abort if linking the class throws an exception.
759
760 // Use a test to avoid redundantly resetting the state if there's
761 // no change. Set_init_state() asserts that state changes make
762 // progress, whereas here we might just be spinning in place.
763 if (old_state != _init_state)
764 set_init_state(old_state);
765 } else {
766 // linking successfull, mark class as initialized
767 set_init_state(fully_initialized);
768 fence_and_clear_init_lock();
769 // trace
770 if (log_is_enabled(Info, class, init)) {
771 ResourceMark rm(THREAD);
772 log_info(class, init)("[Initialized %s without side effects]", external_name());
773 }
774 }
775 }
776
777
778 // See "The Virtual Machine Specification" section 2.16.5 for a detailed explanation of the class initialization
779 // process. The step comments refers to the procedure described in that section.
780 // Note: implementation moved to static method to expose the this pointer.
781 void InstanceKlass::initialize(TRAPS) {
782 if (this->should_be_initialized()) {
783 initialize_impl(CHECK);
784 // Note: at this point the class may be initialized
785 // OR it may be in the state of being initialized
786 // in case of recursive initialization!
787 } else {
788 assert(is_initialized(), "sanity check");
789 }
790 }
791
792
793 bool InstanceKlass::verify_code(TRAPS) {
794 // 1) Verify the bytecodes
795 return Verifier::verify(this, should_verify_class(), THREAD);
796 }
797
798 void InstanceKlass::link_class(TRAPS) {
799 assert(is_loaded(), "must be loaded");
800 if (!is_linked()) {
801 link_class_impl(CHECK);
802 }
803 }
804
805 // Called to verify that a class can link during initialization, without
806 // throwing a VerifyError.
807 bool InstanceKlass::link_class_or_fail(TRAPS) {
808 assert(is_loaded(), "must be loaded");
809 if (!is_linked()) {
810 link_class_impl(CHECK_false);
811 }
812 return is_linked();
813 }
814
815 bool InstanceKlass::link_class_impl(TRAPS) {
816 if (DumpSharedSpaces && SystemDictionaryShared::has_class_failed_verification(this)) {
817 // This is for CDS dumping phase only -- we use the in_error_state to indicate that
818 // the class has failed verification. Throwing the NoClassDefFoundError here is just
819 // a convenient way to stop repeat attempts to verify the same (bad) class.
820 //
821 // Note that the NoClassDefFoundError is not part of the JLS, and should not be thrown
822 // if we are executing Java code. This is not a problem for CDS dumping phase since
823 // it doesn't execute any Java code.
824 ResourceMark rm(THREAD);
825 Exceptions::fthrow(THREAD_AND_LOCATION,
826 vmSymbols::java_lang_NoClassDefFoundError(),
827 "Class %s, or one of its supertypes, failed class initialization",
828 external_name());
829 return false;
830 }
831 // return if already verified
832 if (is_linked()) {
833 return true;
834 }
835
836 // Timing
837 // timer handles recursion
838 assert(THREAD->is_Java_thread(), "non-JavaThread in link_class_impl");
839 JavaThread* jt = (JavaThread*)THREAD;
840
841 // link super class before linking this class
842 Klass* super_klass = super();
843 if (super_klass != NULL) {
844 if (super_klass->is_interface()) { // check if super class is an interface
845 ResourceMark rm(THREAD);
846 Exceptions::fthrow(
847 THREAD_AND_LOCATION,
848 vmSymbols::java_lang_IncompatibleClassChangeError(),
849 "class %s has interface %s as super class",
850 external_name(),
851 super_klass->external_name()
852 );
853 return false;
854 }
855
856 InstanceKlass* ik_super = InstanceKlass::cast(super_klass);
857 ik_super->link_class_impl(CHECK_false);
858 }
859
860 // link all interfaces implemented by this class before linking this class
861 Array<InstanceKlass*>* interfaces = local_interfaces();
862 int num_interfaces = interfaces->length();
863 for (int index = 0; index < num_interfaces; index++) {
864 InstanceKlass* interk = interfaces->at(index);
865 interk->link_class_impl(CHECK_false);
866 }
867
868 // in case the class is linked in the process of linking its superclasses
869 if (is_linked()) {
870 return true;
871 }
872
873 // trace only the link time for this klass that includes
874 // the verification time
875 PerfClassTraceTime vmtimer(ClassLoader::perf_class_link_time(),
876 ClassLoader::perf_class_link_selftime(),
877 ClassLoader::perf_classes_linked(),
878 jt->get_thread_stat()->perf_recursion_counts_addr(),
879 jt->get_thread_stat()->perf_timers_addr(),
880 PerfClassTraceTime::CLASS_LINK);
881
882 // verification & rewriting
883 {
884 HandleMark hm(THREAD);
885 Handle h_init_lock(THREAD, init_lock());
886 ObjectLocker ol(h_init_lock, THREAD, h_init_lock() != NULL);
887 // rewritten will have been set if loader constraint error found
888 // on an earlier link attempt
889 // don't verify or rewrite if already rewritten
890 //
891
892 if (!is_linked()) {
893 if (!is_rewritten()) {
894 {
895 bool verify_ok = verify_code(THREAD);
896 if (!verify_ok) {
897 return false;
898 }
899 }
900
901 // Just in case a side-effect of verify linked this class already
902 // (which can sometimes happen since the verifier loads classes
903 // using custom class loaders, which are free to initialize things)
904 if (is_linked()) {
905 return true;
906 }
907
908 // also sets rewritten
909 rewrite_class(CHECK_false);
910 } else if (is_shared()) {
911 SystemDictionaryShared::check_verification_constraints(this, CHECK_false);
912 }
913
914 // relocate jsrs and link methods after they are all rewritten
915 link_methods(CHECK_false);
916
917 // Initialize the vtable and interface table after
918 // methods have been rewritten since rewrite may
919 // fabricate new Method*s.
920 // also does loader constraint checking
921 //
922 // initialize_vtable and initialize_itable need to be rerun for
923 // a shared class if the class is not loaded by the NULL classloader.
924 ClassLoaderData * loader_data = class_loader_data();
925 if (!(is_shared() &&
926 loader_data->is_the_null_class_loader_data())) {
927 vtable().initialize_vtable(true, CHECK_false);
928 itable().initialize_itable(true, CHECK_false);
929 }
930 #ifdef ASSERT
931 else {
932 vtable().verify(tty, true);
933 // In case itable verification is ever added.
934 // itable().verify(tty, true);
935 }
936 #endif
937 set_init_state(linked);
938 if (JvmtiExport::should_post_class_prepare()) {
939 Thread *thread = THREAD;
940 assert(thread->is_Java_thread(), "thread->is_Java_thread()");
941 JvmtiExport::post_class_prepare((JavaThread *) thread, this);
942 }
943 }
944 }
945 return true;
946 }
947
948 // Rewrite the byte codes of all of the methods of a class.
949 // The rewriter must be called exactly once. Rewriting must happen after
950 // verification but before the first method of the class is executed.
951 void InstanceKlass::rewrite_class(TRAPS) {
952 assert(is_loaded(), "must be loaded");
953 if (is_rewritten()) {
954 assert(is_shared(), "rewriting an unshared class?");
955 return;
956 }
957 Rewriter::rewrite(this, CHECK);
958 set_rewritten();
959 }
960
961 // Now relocate and link method entry points after class is rewritten.
962 // This is outside is_rewritten flag. In case of an exception, it can be
963 // executed more than once.
964 void InstanceKlass::link_methods(TRAPS) {
965 int len = methods()->length();
966 for (int i = len-1; i >= 0; i--) {
967 methodHandle m(THREAD, methods()->at(i));
968
969 // Set up method entry points for compiler and interpreter .
970 m->link_method(m, CHECK);
971 }
972 }
973
974 // Eagerly initialize superinterfaces that declare default methods (concrete instance: any access)
975 void InstanceKlass::initialize_super_interfaces(TRAPS) {
976 assert (has_nonstatic_concrete_methods(), "caller should have checked this");
977 for (int i = 0; i < local_interfaces()->length(); ++i) {
978 InstanceKlass* ik = local_interfaces()->at(i);
979
980 // Initialization is depth first search ie. we start with top of the inheritance tree
981 // has_nonstatic_concrete_methods drives searching superinterfaces since it
982 // means has_nonstatic_concrete_methods in its superinterface hierarchy
983 if (ik->has_nonstatic_concrete_methods()) {
984 ik->initialize_super_interfaces(CHECK);
985 }
986
987 // Only initialize() interfaces that "declare" concrete methods.
988 if (ik->should_be_initialized() && ik->declares_nonstatic_concrete_methods()) {
989 ik->initialize(CHECK);
990 }
991 }
992 }
993
994 void InstanceKlass::initialize_impl(TRAPS) {
995 HandleMark hm(THREAD);
996
997 // Make sure klass is linked (verified) before initialization
998 // A class could already be verified, since it has been reflected upon.
999 link_class(CHECK);
1000
1001 DTRACE_CLASSINIT_PROBE(required, -1);
1002
1003 bool wait = false;
1004
1005 assert(THREAD->is_Java_thread(), "non-JavaThread in initialize_impl");
1006 JavaThread* jt = (JavaThread*)THREAD;
1007
1008 // refer to the JVM book page 47 for description of steps
1009 // Step 1
1010 {
1011 Handle h_init_lock(THREAD, init_lock());
1012 ObjectLocker ol(h_init_lock, THREAD, h_init_lock() != NULL);
1013
1014 // Step 2
1015 // If we were to use wait() instead of waitInterruptibly() then
1016 // we might end up throwing IE from link/symbol resolution sites
1017 // that aren't expected to throw. This would wreak havoc. See 6320309.
1018 while (is_being_initialized() && !is_reentrant_initialization(jt)) {
1019 wait = true;
1020 jt->set_class_to_be_initialized(this);
1021 ol.wait_uninterruptibly(jt);
1022 jt->set_class_to_be_initialized(NULL);
1023 }
1024
1025 // Step 3
1026 if (is_being_initialized() && is_reentrant_initialization(jt)) {
1027 DTRACE_CLASSINIT_PROBE_WAIT(recursive, -1, wait);
1028 return;
1029 }
1030
1031 // Step 4
1032 if (is_initialized()) {
1033 DTRACE_CLASSINIT_PROBE_WAIT(concurrent, -1, wait);
1034 return;
1035 }
1036
1037 // Step 5
1038 if (is_in_error_state()) {
1039 DTRACE_CLASSINIT_PROBE_WAIT(erroneous, -1, wait);
1040 ResourceMark rm(THREAD);
1041 const char* desc = "Could not initialize class ";
1042 const char* className = external_name();
1043 size_t msglen = strlen(desc) + strlen(className) + 1;
1044 char* message = NEW_RESOURCE_ARRAY(char, msglen);
1045 if (NULL == message) {
1046 // Out of memory: can't create detailed error message
1047 THROW_MSG(vmSymbols::java_lang_NoClassDefFoundError(), className);
1048 } else {
1049 jio_snprintf(message, msglen, "%s%s", desc, className);
1050 THROW_MSG(vmSymbols::java_lang_NoClassDefFoundError(), message);
1051 }
1052 }
1053
1054 // Step 6
1055 set_init_state(being_initialized);
1056 set_init_thread(jt);
1057 }
1058
1059 // Step 7
1060 // Next, if C is a class rather than an interface, initialize it's super class and super
1061 // interfaces.
1062 if (!is_interface()) {
1063 Klass* super_klass = super();
1064 if (super_klass != NULL && super_klass->should_be_initialized()) {
1065 super_klass->initialize(THREAD);
1066 }
1067 // If C implements any interface that declares a non-static, concrete method,
1068 // the initialization of C triggers initialization of its super interfaces.
1069 // Only need to recurse if has_nonstatic_concrete_methods which includes declaring and
1070 // having a superinterface that declares, non-static, concrete methods
1071 if (!HAS_PENDING_EXCEPTION && has_nonstatic_concrete_methods()) {
1072 initialize_super_interfaces(THREAD);
1073 }
1074
1075 // If any exceptions, complete abruptly, throwing the same exception as above.
1076 if (HAS_PENDING_EXCEPTION) {
1077 Handle e(THREAD, PENDING_EXCEPTION);
1078 CLEAR_PENDING_EXCEPTION;
1079 {
1080 EXCEPTION_MARK;
1081 // Locks object, set state, and notify all waiting threads
1082 set_initialization_state_and_notify(initialization_error, THREAD);
1083 CLEAR_PENDING_EXCEPTION;
1084 }
1085 DTRACE_CLASSINIT_PROBE_WAIT(super__failed, -1, wait);
1086 THROW_OOP(e());
1087 }
1088 }
1089
1090
1091 // Look for aot compiled methods for this klass, including class initializer.
1092 AOTLoader::load_for_klass(this, THREAD);
1093
1094 // Step 8
1095 {
1096 DTRACE_CLASSINIT_PROBE_WAIT(clinit, -1, wait);
1097 // Timer includes any side effects of class initialization (resolution,
1098 // etc), but not recursive entry into call_class_initializer().
1099 PerfClassTraceTime timer(ClassLoader::perf_class_init_time(),
1100 ClassLoader::perf_class_init_selftime(),
1101 ClassLoader::perf_classes_inited(),
1102 jt->get_thread_stat()->perf_recursion_counts_addr(),
1103 jt->get_thread_stat()->perf_timers_addr(),
1104 PerfClassTraceTime::CLASS_CLINIT);
1105 call_class_initializer(THREAD);
1106 }
1107
1108 // Step 9
1109 if (!HAS_PENDING_EXCEPTION) {
1110 set_initialization_state_and_notify(fully_initialized, CHECK);
1111 {
1112 debug_only(vtable().verify(tty, true);)
1113 }
1114 }
1115 else {
1116 // Step 10 and 11
1117 Handle e(THREAD, PENDING_EXCEPTION);
1118 CLEAR_PENDING_EXCEPTION;
1119 // JVMTI has already reported the pending exception
1120 // JVMTI internal flag reset is needed in order to report ExceptionInInitializerError
1121 JvmtiExport::clear_detected_exception(jt);
1122 {
1123 EXCEPTION_MARK;
1124 set_initialization_state_and_notify(initialization_error, THREAD);
1125 CLEAR_PENDING_EXCEPTION; // ignore any exception thrown, class initialization error is thrown below
1126 // JVMTI has already reported the pending exception
1127 // JVMTI internal flag reset is needed in order to report ExceptionInInitializerError
1128 JvmtiExport::clear_detected_exception(jt);
1129 }
1130 DTRACE_CLASSINIT_PROBE_WAIT(error, -1, wait);
1131 if (e->is_a(SystemDictionary::Error_klass())) {
1132 THROW_OOP(e());
1133 } else {
1134 JavaCallArguments args(e);
1135 THROW_ARG(vmSymbols::java_lang_ExceptionInInitializerError(),
1136 vmSymbols::throwable_void_signature(),
1137 &args);
1138 }
1139 }
1140 DTRACE_CLASSINIT_PROBE_WAIT(end, -1, wait);
1141 }
1142
1143
1144 void InstanceKlass::set_initialization_state_and_notify(ClassState state, TRAPS) {
1145 Handle h_init_lock(THREAD, init_lock());
1146 if (h_init_lock() != NULL) {
1147 ObjectLocker ol(h_init_lock, THREAD);
1148 set_init_thread(NULL); // reset _init_thread before changing _init_state
1149 set_init_state(state);
1150 fence_and_clear_init_lock();
1151 ol.notify_all(CHECK);
1152 } else {
1153 assert(h_init_lock() != NULL, "The initialization state should never be set twice");
1154 set_init_thread(NULL); // reset _init_thread before changing _init_state
1155 set_init_state(state);
1156 }
1157 }
1158
1159 Klass* InstanceKlass::implementor() const {
1160 Klass* volatile* k = adr_implementor();
1161 if (k == NULL) {
1162 return NULL;
1163 } else {
1164 // This load races with inserts, and therefore needs acquire.
1165 Klass* kls = Atomic::load_acquire(k);
1166 if (kls != NULL && !kls->is_loader_alive()) {
1167 return NULL; // don't return unloaded class
1168 } else {
1169 return kls;
1170 }
1171 }
1172 }
1173
1174
1175 void InstanceKlass::set_implementor(Klass* k) {
1176 assert_locked_or_safepoint(Compile_lock);
1177 assert(is_interface(), "not interface");
1178 Klass* volatile* addr = adr_implementor();
1179 assert(addr != NULL, "null addr");
1180 if (addr != NULL) {
1181 Atomic::release_store(addr, k);
1182 }
1183 }
1184
1185 int InstanceKlass::nof_implementors() const {
1186 Klass* k = implementor();
1187 if (k == NULL) {
1188 return 0;
1189 } else if (k != this) {
1190 return 1;
1191 } else {
1192 return 2;
1193 }
1194 }
1195
1196 // The embedded _implementor field can only record one implementor.
1197 // When there are more than one implementors, the _implementor field
1198 // is set to the interface Klass* itself. Following are the possible
1199 // values for the _implementor field:
1200 // NULL - no implementor
1201 // implementor Klass* - one implementor
1202 // self - more than one implementor
1203 //
1204 // The _implementor field only exists for interfaces.
1205 void InstanceKlass::add_implementor(Klass* k) {
1206 if (Universe::is_fully_initialized()) {
1207 assert_lock_strong(Compile_lock);
1208 }
1209 assert(is_interface(), "not interface");
1210 // Filter out my subinterfaces.
1211 // (Note: Interfaces are never on the subklass list.)
1212 if (InstanceKlass::cast(k)->is_interface()) return;
1213
1214 // Filter out subclasses whose supers already implement me.
1215 // (Note: CHA must walk subclasses of direct implementors
1216 // in order to locate indirect implementors.)
1217 Klass* sk = k->super();
1218 if (sk != NULL && InstanceKlass::cast(sk)->implements_interface(this))
1219 // We only need to check one immediate superclass, since the
1220 // implements_interface query looks at transitive_interfaces.
1221 // Any supers of the super have the same (or fewer) transitive_interfaces.
1222 return;
1223
1224 Klass* ik = implementor();
1225 if (ik == NULL) {
1226 set_implementor(k);
1227 } else if (ik != this && ik != k) {
1228 // There is already an implementor. Use itself as an indicator of
1229 // more than one implementors.
1230 set_implementor(this);
1231 }
1232
1233 // The implementor also implements the transitive_interfaces
1234 for (int index = 0; index < local_interfaces()->length(); index++) {
1235 InstanceKlass::cast(local_interfaces()->at(index))->add_implementor(k);
1236 }
1237 }
1238
1239 void InstanceKlass::init_implementor() {
1240 if (is_interface()) {
1241 set_implementor(NULL);
1242 }
1243 }
1244
1245
1246 void InstanceKlass::process_interfaces(Thread *thread) {
1247 // link this class into the implementors list of every interface it implements
1248 for (int i = local_interfaces()->length() - 1; i >= 0; i--) {
1249 assert(local_interfaces()->at(i)->is_klass(), "must be a klass");
1250 InstanceKlass* interf = InstanceKlass::cast(local_interfaces()->at(i));
1251 assert(interf->is_interface(), "expected interface");
1252 interf->add_implementor(this);
1253 }
1254 }
1255
1256 bool InstanceKlass::can_be_primary_super_slow() const {
1257 if (is_interface())
1258 return false;
1259 else
1260 return Klass::can_be_primary_super_slow();
1261 }
1262
1263 GrowableArray<Klass*>* InstanceKlass::compute_secondary_supers(int num_extra_slots,
1264 Array<InstanceKlass*>* transitive_interfaces) {
1265 // The secondaries are the implemented interfaces.
1266 Array<InstanceKlass*>* interfaces = transitive_interfaces;
1267 int num_secondaries = num_extra_slots + interfaces->length();
1268 if (num_secondaries == 0) {
1269 // Must share this for correct bootstrapping!
1270 set_secondary_supers(Universe::the_empty_klass_array());
1271 return NULL;
1272 } else if (num_extra_slots == 0) {
1273 // The secondary super list is exactly the same as the transitive interfaces, so
1274 // let's use it instead of making a copy.
1275 // Redefine classes has to be careful not to delete this!
1276 // We need the cast because Array<Klass*> is NOT a supertype of Array<InstanceKlass*>,
1277 // (but it's safe to do here because we won't write into _secondary_supers from this point on).
1278 set_secondary_supers((Array<Klass*>*)(address)interfaces);
1279 return NULL;
1280 } else {
1281 // Copy transitive interfaces to a temporary growable array to be constructed
1282 // into the secondary super list with extra slots.
1283 GrowableArray<Klass*>* secondaries = new GrowableArray<Klass*>(interfaces->length());
1284 for (int i = 0; i < interfaces->length(); i++) {
1285 secondaries->push(interfaces->at(i));
1286 }
1287 return secondaries;
1288 }
1289 }
1290
1291 bool InstanceKlass::implements_interface(Klass* k) const {
1292 if (this == k) return true;
1293 assert(k->is_interface(), "should be an interface class");
1294 for (int i = 0; i < transitive_interfaces()->length(); i++) {
1295 if (transitive_interfaces()->at(i) == k) {
1296 return true;
1297 }
1298 }
1299 return false;
1300 }
1301
1302 bool InstanceKlass::is_same_or_direct_interface(Klass *k) const {
1303 // Verify direct super interface
1304 if (this == k) return true;
1305 assert(k->is_interface(), "should be an interface class");
1306 for (int i = 0; i < local_interfaces()->length(); i++) {
1307 if (local_interfaces()->at(i) == k) {
1308 return true;
1309 }
1310 }
1311 return false;
1312 }
1313
1314 objArrayOop InstanceKlass::allocate_objArray(int n, int length, TRAPS) {
1315 check_array_allocation_length(length, arrayOopDesc::max_array_length(T_OBJECT), CHECK_NULL);
1316 int size = objArrayOopDesc::object_size(length);
1317 Klass* ak = array_klass(n, CHECK_NULL);
1318 objArrayOop o = (objArrayOop)Universe::heap()->array_allocate(ak, size, length,
1319 /* do_zero */ true, CHECK_NULL);
1320 return o;
1321 }
1322
1323 instanceOop InstanceKlass::register_finalizer(instanceOop i, TRAPS) {
1324 if (TraceFinalizerRegistration) {
1325 tty->print("Registered ");
1326 i->print_value_on(tty);
1327 tty->print_cr(" (" INTPTR_FORMAT ") as finalizable", p2i(i));
1328 }
1329 instanceHandle h_i(THREAD, i);
1330 // Pass the handle as argument, JavaCalls::call expects oop as jobjects
1331 JavaValue result(T_VOID);
1332 JavaCallArguments args(h_i);
1333 methodHandle mh (THREAD, Universe::finalizer_register_method());
1334 JavaCalls::call(&result, mh, &args, CHECK_NULL);
1335 return h_i();
1336 }
1337
1338 instanceOop InstanceKlass::allocate_instance(TRAPS) {
1339 bool has_finalizer_flag = has_finalizer(); // Query before possible GC
1340 int size = size_helper(); // Query before forming handle.
1341
1342 instanceOop i;
1343
1344 i = (instanceOop)Universe::heap()->obj_allocate(this, size, CHECK_NULL);
1345 if (has_finalizer_flag && !RegisterFinalizersAtInit) {
1346 i = register_finalizer(i, CHECK_NULL);
1347 }
1348 return i;
1349 }
1350
1351 instanceHandle InstanceKlass::allocate_instance_handle(TRAPS) {
1352 return instanceHandle(THREAD, allocate_instance(THREAD));
1353 }
1354
1355 void InstanceKlass::check_valid_for_instantiation(bool throwError, TRAPS) {
1356 if (is_interface() || is_abstract()) {
1357 ResourceMark rm(THREAD);
1358 THROW_MSG(throwError ? vmSymbols::java_lang_InstantiationError()
1359 : vmSymbols::java_lang_InstantiationException(), external_name());
1360 }
1361 if (this == SystemDictionary::Class_klass()) {
1362 ResourceMark rm(THREAD);
1363 THROW_MSG(throwError ? vmSymbols::java_lang_IllegalAccessError()
1364 : vmSymbols::java_lang_IllegalAccessException(), external_name());
1365 }
1366 }
1367
1368 Klass* InstanceKlass::array_klass_impl(bool or_null, int n, TRAPS) {
1369 // Need load-acquire for lock-free read
1370 if (array_klasses_acquire() == NULL) {
1371 if (or_null) return NULL;
1372
1373 ResourceMark rm(THREAD);
1374 JavaThread *jt = (JavaThread *)THREAD;
1375 {
1376 // Atomic creation of array_klasses
1377 MutexLocker ma(THREAD, MultiArray_lock);
1378
1379 // Check if update has already taken place
1380 if (array_klasses() == NULL) {
1381 Klass* k = ObjArrayKlass::allocate_objArray_klass(class_loader_data(), 1, this, CHECK_NULL);
1382 // use 'release' to pair with lock-free load
1383 release_set_array_klasses(k);
1384 }
1385 }
1386 }
1387 // _this will always be set at this point
1388 ObjArrayKlass* oak = (ObjArrayKlass*)array_klasses();
1389 if (or_null) {
1390 return oak->array_klass_or_null(n);
1391 }
1392 return oak->array_klass(n, THREAD);
1393 }
1394
1395 Klass* InstanceKlass::array_klass_impl(bool or_null, TRAPS) {
1396 return array_klass_impl(or_null, 1, THREAD);
1397 }
1398
1399 static int call_class_initializer_counter = 0; // for debugging
1400
1401 Method* InstanceKlass::class_initializer() const {
1402 Method* clinit = find_method(
1403 vmSymbols::class_initializer_name(), vmSymbols::void_method_signature());
1404 if (clinit != NULL && clinit->has_valid_initializer_flags()) {
1405 return clinit;
1406 }
1407 return NULL;
1408 }
1409
1410 void InstanceKlass::call_class_initializer(TRAPS) {
1411 if (ReplayCompiles &&
1412 (ReplaySuppressInitializers == 1 ||
1413 (ReplaySuppressInitializers >= 2 && class_loader() != NULL))) {
1414 // Hide the existence of the initializer for the purpose of replaying the compile
1415 return;
1416 }
1417
1418 methodHandle h_method(THREAD, class_initializer());
1419 assert(!is_initialized(), "we cannot initialize twice");
1420 LogTarget(Info, class, init) lt;
1421 if (lt.is_enabled()) {
1422 ResourceMark rm(THREAD);
1423 LogStream ls(lt);
1424 ls.print("%d Initializing ", call_class_initializer_counter++);
1425 name()->print_value_on(&ls);
1426 ls.print_cr("%s (" INTPTR_FORMAT ")", h_method() == NULL ? "(no method)" : "", p2i(this));
1427 }
1428 if (h_method() != NULL) {
1429 JavaCallArguments args; // No arguments
1430 JavaValue result(T_VOID);
1431 JavaCalls::call(&result, h_method, &args, CHECK); // Static call (no args)
1432 }
1433 }
1434
1435
1436 void InstanceKlass::mask_for(const methodHandle& method, int bci,
1437 InterpreterOopMap* entry_for) {
1438 // Lazily create the _oop_map_cache at first request
1439 // Lock-free access requires load_acquire.
1440 OopMapCache* oop_map_cache = Atomic::load_acquire(&_oop_map_cache);
1441 if (oop_map_cache == NULL) {
1442 MutexLocker x(OopMapCacheAlloc_lock);
1443 // Check if _oop_map_cache was allocated while we were waiting for this lock
1444 if ((oop_map_cache = _oop_map_cache) == NULL) {
1445 oop_map_cache = new OopMapCache();
1446 // Ensure _oop_map_cache is stable, since it is examined without a lock
1447 Atomic::release_store(&_oop_map_cache, oop_map_cache);
1448 }
1449 }
1450 // _oop_map_cache is constant after init; lookup below does its own locking.
1451 oop_map_cache->lookup(method, bci, entry_for);
1452 }
1453
1454 bool InstanceKlass::contains_field_offset(int offset) {
1455 fieldDescriptor fd;
1456 return find_field_from_offset(offset, false, &fd);
1457 }
1458
1459 bool InstanceKlass::find_local_field(Symbol* name, Symbol* sig, fieldDescriptor* fd) const {
1460 for (JavaFieldStream fs(this); !fs.done(); fs.next()) {
1461 Symbol* f_name = fs.name();
1462 Symbol* f_sig = fs.signature();
1463 if (f_name == name && f_sig == sig) {
1464 fd->reinitialize(const_cast<InstanceKlass*>(this), fs.index());
1465 return true;
1466 }
1467 }
1468 return false;
1469 }
1470
1471
1472 Klass* InstanceKlass::find_interface_field(Symbol* name, Symbol* sig, fieldDescriptor* fd) const {
1473 const int n = local_interfaces()->length();
1474 for (int i = 0; i < n; i++) {
1475 Klass* intf1 = local_interfaces()->at(i);
1476 assert(intf1->is_interface(), "just checking type");
1477 // search for field in current interface
1478 if (InstanceKlass::cast(intf1)->find_local_field(name, sig, fd)) {
1479 assert(fd->is_static(), "interface field must be static");
1480 return intf1;
1481 }
1482 // search for field in direct superinterfaces
1483 Klass* intf2 = InstanceKlass::cast(intf1)->find_interface_field(name, sig, fd);
1484 if (intf2 != NULL) return intf2;
1485 }
1486 // otherwise field lookup fails
1487 return NULL;
1488 }
1489
1490
1491 Klass* InstanceKlass::find_field(Symbol* name, Symbol* sig, fieldDescriptor* fd) const {
1492 // search order according to newest JVM spec (5.4.3.2, p.167).
1493 // 1) search for field in current klass
1494 if (find_local_field(name, sig, fd)) {
1495 return const_cast<InstanceKlass*>(this);
1496 }
1497 // 2) search for field recursively in direct superinterfaces
1498 { Klass* intf = find_interface_field(name, sig, fd);
1499 if (intf != NULL) return intf;
1500 }
1501 // 3) apply field lookup recursively if superclass exists
1502 { Klass* supr = super();
1503 if (supr != NULL) return InstanceKlass::cast(supr)->find_field(name, sig, fd);
1504 }
1505 // 4) otherwise field lookup fails
1506 return NULL;
1507 }
1508
1509
1510 Klass* InstanceKlass::find_field(Symbol* name, Symbol* sig, bool is_static, fieldDescriptor* fd) const {
1511 // search order according to newest JVM spec (5.4.3.2, p.167).
1512 // 1) search for field in current klass
1513 if (find_local_field(name, sig, fd)) {
1514 if (fd->is_static() == is_static) return const_cast<InstanceKlass*>(this);
1515 }
1516 // 2) search for field recursively in direct superinterfaces
1517 if (is_static) {
1518 Klass* intf = find_interface_field(name, sig, fd);
1519 if (intf != NULL) return intf;
1520 }
1521 // 3) apply field lookup recursively if superclass exists
1522 { Klass* supr = super();
1523 if (supr != NULL) return InstanceKlass::cast(supr)->find_field(name, sig, is_static, fd);
1524 }
1525 // 4) otherwise field lookup fails
1526 return NULL;
1527 }
1528
1529
1530 bool InstanceKlass::find_local_field_from_offset(int offset, bool is_static, fieldDescriptor* fd) const {
1531 for (JavaFieldStream fs(this); !fs.done(); fs.next()) {
1532 if (fs.offset() == offset) {
1533 fd->reinitialize(const_cast<InstanceKlass*>(this), fs.index());
1534 if (fd->is_static() == is_static) return true;
1535 }
1536 }
1537 return false;
1538 }
1539
1540
1541 bool InstanceKlass::find_field_from_offset(int offset, bool is_static, fieldDescriptor* fd) const {
1542 Klass* klass = const_cast<InstanceKlass*>(this);
1543 while (klass != NULL) {
1544 if (InstanceKlass::cast(klass)->find_local_field_from_offset(offset, is_static, fd)) {
1545 return true;
1546 }
1547 klass = klass->super();
1548 }
1549 return false;
1550 }
1551
1552
1553 void InstanceKlass::methods_do(void f(Method* method)) {
1554 // Methods aren't stable until they are loaded. This can be read outside
1555 // a lock through the ClassLoaderData for profiling
1556 if (!is_loaded()) {
1557 return;
1558 }
1559
1560 int len = methods()->length();
1561 for (int index = 0; index < len; index++) {
1562 Method* m = methods()->at(index);
1563 assert(m->is_method(), "must be method");
1564 f(m);
1565 }
1566 }
1567
1568
1569 void InstanceKlass::do_local_static_fields(FieldClosure* cl) {
1570 for (JavaFieldStream fs(this); !fs.done(); fs.next()) {
1571 if (fs.access_flags().is_static()) {
1572 fieldDescriptor& fd = fs.field_descriptor();
1573 cl->do_field(&fd);
1574 }
1575 }
1576 }
1577
1578
1579 void InstanceKlass::do_local_static_fields(void f(fieldDescriptor*, Handle, TRAPS), Handle mirror, TRAPS) {
1580 for (JavaFieldStream fs(this); !fs.done(); fs.next()) {
1581 if (fs.access_flags().is_static()) {
1582 fieldDescriptor& fd = fs.field_descriptor();
1583 f(&fd, mirror, CHECK);
1584 }
1585 }
1586 }
1587
1588
1589 static int compare_fields_by_offset(int* a, int* b) {
1590 return a[0] - b[0];
1591 }
1592
1593 void InstanceKlass::do_nonstatic_fields(FieldClosure* cl) {
1594 InstanceKlass* super = superklass();
1595 if (super != NULL) {
1596 super->do_nonstatic_fields(cl);
1597 }
1598 fieldDescriptor fd;
1599 int length = java_fields_count();
1600 // In DebugInfo nonstatic fields are sorted by offset.
1601 int* fields_sorted = NEW_C_HEAP_ARRAY(int, 2*(length+1), mtClass);
1602 int j = 0;
1603 for (int i = 0; i < length; i += 1) {
1604 fd.reinitialize(this, i);
1605 if (!fd.is_static()) {
1606 fields_sorted[j + 0] = fd.offset();
1607 fields_sorted[j + 1] = i;
1608 j += 2;
1609 }
1610 }
1611 if (j > 0) {
1612 length = j;
1613 // _sort_Fn is defined in growableArray.hpp.
1614 qsort(fields_sorted, length/2, 2*sizeof(int), (_sort_Fn)compare_fields_by_offset);
1615 for (int i = 0; i < length; i += 2) {
1616 fd.reinitialize(this, fields_sorted[i + 1]);
1617 assert(!fd.is_static() && fd.offset() == fields_sorted[i], "only nonstatic fields");
1618 cl->do_field(&fd);
1619 }
1620 }
1621 FREE_C_HEAP_ARRAY(int, fields_sorted);
1622 }
1623
1624
1625 void InstanceKlass::array_klasses_do(void f(Klass* k, TRAPS), TRAPS) {
1626 if (array_klasses() != NULL)
1627 ArrayKlass::cast(array_klasses())->array_klasses_do(f, THREAD);
1628 }
1629
1630 void InstanceKlass::array_klasses_do(void f(Klass* k)) {
1631 if (array_klasses() != NULL)
1632 ArrayKlass::cast(array_klasses())->array_klasses_do(f);
1633 }
1634
1635 #ifdef ASSERT
1636 static int linear_search(const Array<Method*>* methods,
1637 const Symbol* name,
1638 const Symbol* signature) {
1639 const int len = methods->length();
1640 for (int index = 0; index < len; index++) {
1641 const Method* const m = methods->at(index);
1642 assert(m->is_method(), "must be method");
1643 if (m->signature() == signature && m->name() == name) {
1644 return index;
1645 }
1646 }
1647 return -1;
1648 }
1649 #endif
1650
1651 bool InstanceKlass::_disable_method_binary_search = false;
1652
1653 NOINLINE int linear_search(const Array<Method*>* methods, const Symbol* name) {
1654 int len = methods->length();
1655 int l = 0;
1656 int h = len - 1;
1657 while (l <= h) {
1658 Method* m = methods->at(l);
1659 if (m->name() == name) {
1660 return l;
1661 }
1662 l++;
1663 }
1664 return -1;
1665 }
1666
1667 inline int InstanceKlass::quick_search(const Array<Method*>* methods, const Symbol* name) {
1668 if (_disable_method_binary_search) {
1669 assert(DynamicDumpSharedSpaces, "must be");
1670 // At the final stage of dynamic dumping, the methods array may not be sorted
1671 // by ascending addresses of their names, so we can't use binary search anymore.
1672 // However, methods with the same name are still laid out consecutively inside the
1673 // methods array, so let's look for the first one that matches.
1674 return linear_search(methods, name);
1675 }
1676
1677 int len = methods->length();
1678 int l = 0;
1679 int h = len - 1;
1680
1681 // methods are sorted by ascending addresses of their names, so do binary search
1682 while (l <= h) {
1683 int mid = (l + h) >> 1;
1684 Method* m = methods->at(mid);
1685 assert(m->is_method(), "must be method");
1686 int res = m->name()->fast_compare(name);
1687 if (res == 0) {
1688 return mid;
1689 } else if (res < 0) {
1690 l = mid + 1;
1691 } else {
1692 h = mid - 1;
1693 }
1694 }
1695 return -1;
1696 }
1697
1698 // find_method looks up the name/signature in the local methods array
1699 Method* InstanceKlass::find_method(const Symbol* name,
1700 const Symbol* signature) const {
1701 return find_method_impl(name, signature, find_overpass, find_static, find_private);
1702 }
1703
1704 Method* InstanceKlass::find_method_impl(const Symbol* name,
1705 const Symbol* signature,
1706 OverpassLookupMode overpass_mode,
1707 StaticLookupMode static_mode,
1708 PrivateLookupMode private_mode) const {
1709 return InstanceKlass::find_method_impl(methods(),
1710 name,
1711 signature,
1712 overpass_mode,
1713 static_mode,
1714 private_mode);
1715 }
1716
1717 // find_instance_method looks up the name/signature in the local methods array
1718 // and skips over static methods
1719 Method* InstanceKlass::find_instance_method(const Array<Method*>* methods,
1720 const Symbol* name,
1721 const Symbol* signature,
1722 PrivateLookupMode private_mode) {
1723 Method* const meth = InstanceKlass::find_method_impl(methods,
1724 name,
1725 signature,
1726 find_overpass,
1727 skip_static,
1728 private_mode);
1729 assert(((meth == NULL) || !meth->is_static()),
1730 "find_instance_method should have skipped statics");
1731 return meth;
1732 }
1733
1734 // find_instance_method looks up the name/signature in the local methods array
1735 // and skips over static methods
1736 Method* InstanceKlass::find_instance_method(const Symbol* name,
1737 const Symbol* signature,
1738 PrivateLookupMode private_mode) const {
1739 return InstanceKlass::find_instance_method(methods(), name, signature, private_mode);
1740 }
1741
1742 // Find looks up the name/signature in the local methods array
1743 // and filters on the overpass, static and private flags
1744 // This returns the first one found
1745 // note that the local methods array can have up to one overpass, one static
1746 // and one instance (private or not) with the same name/signature
1747 Method* InstanceKlass::find_local_method(const Symbol* name,
1748 const Symbol* signature,
1749 OverpassLookupMode overpass_mode,
1750 StaticLookupMode static_mode,
1751 PrivateLookupMode private_mode) const {
1752 return InstanceKlass::find_method_impl(methods(),
1753 name,
1754 signature,
1755 overpass_mode,
1756 static_mode,
1757 private_mode);
1758 }
1759
1760 // Find looks up the name/signature in the local methods array
1761 // and filters on the overpass, static and private flags
1762 // This returns the first one found
1763 // note that the local methods array can have up to one overpass, one static
1764 // and one instance (private or not) with the same name/signature
1765 Method* InstanceKlass::find_local_method(const Array<Method*>* methods,
1766 const Symbol* name,
1767 const Symbol* signature,
1768 OverpassLookupMode overpass_mode,
1769 StaticLookupMode static_mode,
1770 PrivateLookupMode private_mode) {
1771 return InstanceKlass::find_method_impl(methods,
1772 name,
1773 signature,
1774 overpass_mode,
1775 static_mode,
1776 private_mode);
1777 }
1778
1779 Method* InstanceKlass::find_method(const Array<Method*>* methods,
1780 const Symbol* name,
1781 const Symbol* signature) {
1782 return InstanceKlass::find_method_impl(methods,
1783 name,
1784 signature,
1785 find_overpass,
1786 find_static,
1787 find_private);
1788 }
1789
1790 Method* InstanceKlass::find_method_impl(const Array<Method*>* methods,
1791 const Symbol* name,
1792 const Symbol* signature,
1793 OverpassLookupMode overpass_mode,
1794 StaticLookupMode static_mode,
1795 PrivateLookupMode private_mode) {
1796 int hit = find_method_index(methods, name, signature, overpass_mode, static_mode, private_mode);
1797 return hit >= 0 ? methods->at(hit): NULL;
1798 }
1799
1800 // true if method matches signature and conforms to skipping_X conditions.
1801 static bool method_matches(const Method* m,
1802 const Symbol* signature,
1803 bool skipping_overpass,
1804 bool skipping_static,
1805 bool skipping_private) {
1806 return ((m->signature() == signature) &&
1807 (!skipping_overpass || !m->is_overpass()) &&
1808 (!skipping_static || !m->is_static()) &&
1809 (!skipping_private || !m->is_private()));
1810 }
1811
1812 // Used directly for default_methods to find the index into the
1813 // default_vtable_indices, and indirectly by find_method
1814 // find_method_index looks in the local methods array to return the index
1815 // of the matching name/signature. If, overpass methods are being ignored,
1816 // the search continues to find a potential non-overpass match. This capability
1817 // is important during method resolution to prefer a static method, for example,
1818 // over an overpass method.
1819 // There is the possibility in any _method's array to have the same name/signature
1820 // for a static method, an overpass method and a local instance method
1821 // To correctly catch a given method, the search criteria may need
1822 // to explicitly skip the other two. For local instance methods, it
1823 // is often necessary to skip private methods
1824 int InstanceKlass::find_method_index(const Array<Method*>* methods,
1825 const Symbol* name,
1826 const Symbol* signature,
1827 OverpassLookupMode overpass_mode,
1828 StaticLookupMode static_mode,
1829 PrivateLookupMode private_mode) {
1830 const bool skipping_overpass = (overpass_mode == skip_overpass);
1831 const bool skipping_static = (static_mode == skip_static);
1832 const bool skipping_private = (private_mode == skip_private);
1833 const int hit = quick_search(methods, name);
1834 if (hit != -1) {
1835 const Method* const m = methods->at(hit);
1836
1837 // Do linear search to find matching signature. First, quick check
1838 // for common case, ignoring overpasses if requested.
1839 if (method_matches(m, signature, skipping_overpass, skipping_static, skipping_private)) {
1840 return hit;
1841 }
1842
1843 // search downwards through overloaded methods
1844 int i;
1845 for (i = hit - 1; i >= 0; --i) {
1846 const Method* const m = methods->at(i);
1847 assert(m->is_method(), "must be method");
1848 if (m->name() != name) {
1849 break;
1850 }
1851 if (method_matches(m, signature, skipping_overpass, skipping_static, skipping_private)) {
1852 return i;
1853 }
1854 }
1855 // search upwards
1856 for (i = hit + 1; i < methods->length(); ++i) {
1857 const Method* const m = methods->at(i);
1858 assert(m->is_method(), "must be method");
1859 if (m->name() != name) {
1860 break;
1861 }
1862 if (method_matches(m, signature, skipping_overpass, skipping_static, skipping_private)) {
1863 return i;
1864 }
1865 }
1866 // not found
1867 #ifdef ASSERT
1868 const int index = (skipping_overpass || skipping_static || skipping_private) ? -1 :
1869 linear_search(methods, name, signature);
1870 assert(-1 == index, "binary search should have found entry %d", index);
1871 #endif
1872 }
1873 return -1;
1874 }
1875
1876 int InstanceKlass::find_method_by_name(const Symbol* name, int* end) const {
1877 return find_method_by_name(methods(), name, end);
1878 }
1879
1880 int InstanceKlass::find_method_by_name(const Array<Method*>* methods,
1881 const Symbol* name,
1882 int* end_ptr) {
1883 assert(end_ptr != NULL, "just checking");
1884 int start = quick_search(methods, name);
1885 int end = start + 1;
1886 if (start != -1) {
1887 while (start - 1 >= 0 && (methods->at(start - 1))->name() == name) --start;
1888 while (end < methods->length() && (methods->at(end))->name() == name) ++end;
1889 *end_ptr = end;
1890 return start;
1891 }
1892 return -1;
1893 }
1894
1895 // uncached_lookup_method searches both the local class methods array and all
1896 // superclasses methods arrays, skipping any overpass methods in superclasses,
1897 // and possibly skipping private methods.
1898 Method* InstanceKlass::uncached_lookup_method(const Symbol* name,
1899 const Symbol* signature,
1900 OverpassLookupMode overpass_mode,
1901 PrivateLookupMode private_mode) const {
1902 OverpassLookupMode overpass_local_mode = overpass_mode;
1903 const Klass* klass = this;
1904 while (klass != NULL) {
1905 Method* const method = InstanceKlass::cast(klass)->find_method_impl(name,
1906 signature,
1907 overpass_local_mode,
1908 find_static,
1909 private_mode);
1910 if (method != NULL) {
1911 return method;
1912 }
1913 klass = klass->super();
1914 overpass_local_mode = skip_overpass; // Always ignore overpass methods in superclasses
1915 }
1916 return NULL;
1917 }
1918
1919 #ifdef ASSERT
1920 // search through class hierarchy and return true if this class or
1921 // one of the superclasses was redefined
1922 bool InstanceKlass::has_redefined_this_or_super() const {
1923 const Klass* klass = this;
1924 while (klass != NULL) {
1925 if (InstanceKlass::cast(klass)->has_been_redefined()) {
1926 return true;
1927 }
1928 klass = klass->super();
1929 }
1930 return false;
1931 }
1932 #endif
1933
1934 // lookup a method in the default methods list then in all transitive interfaces
1935 // Do NOT return private or static methods
1936 Method* InstanceKlass::lookup_method_in_ordered_interfaces(Symbol* name,
1937 Symbol* signature) const {
1938 Method* m = NULL;
1939 if (default_methods() != NULL) {
1940 m = find_method(default_methods(), name, signature);
1941 }
1942 // Look up interfaces
1943 if (m == NULL) {
1944 m = lookup_method_in_all_interfaces(name, signature, find_defaults);
1945 }
1946 return m;
1947 }
1948
1949 // lookup a method in all the interfaces that this class implements
1950 // Do NOT return private or static methods, new in JDK8 which are not externally visible
1951 // They should only be found in the initial InterfaceMethodRef
1952 Method* InstanceKlass::lookup_method_in_all_interfaces(Symbol* name,
1953 Symbol* signature,
1954 DefaultsLookupMode defaults_mode) const {
1955 Array<InstanceKlass*>* all_ifs = transitive_interfaces();
1956 int num_ifs = all_ifs->length();
1957 InstanceKlass *ik = NULL;
1958 for (int i = 0; i < num_ifs; i++) {
1959 ik = all_ifs->at(i);
1960 Method* m = ik->lookup_method(name, signature);
1961 if (m != NULL && m->is_public() && !m->is_static() &&
1962 ((defaults_mode != skip_defaults) || !m->is_default_method())) {
1963 return m;
1964 }
1965 }
1966 return NULL;
1967 }
1968
1969 /* jni_id_for_impl for jfieldIds only */
1970 JNIid* InstanceKlass::jni_id_for_impl(int offset) {
1971 MutexLocker ml(JfieldIdCreation_lock);
1972 // Retry lookup after we got the lock
1973 JNIid* probe = jni_ids() == NULL ? NULL : jni_ids()->find(offset);
1974 if (probe == NULL) {
1975 // Slow case, allocate new static field identifier
1976 probe = new JNIid(this, offset, jni_ids());
1977 set_jni_ids(probe);
1978 }
1979 return probe;
1980 }
1981
1982
1983 /* jni_id_for for jfieldIds only */
1984 JNIid* InstanceKlass::jni_id_for(int offset) {
1985 JNIid* probe = jni_ids() == NULL ? NULL : jni_ids()->find(offset);
1986 if (probe == NULL) {
1987 probe = jni_id_for_impl(offset);
1988 }
1989 return probe;
1990 }
1991
1992 u2 InstanceKlass::enclosing_method_data(int offset) const {
1993 const Array<jushort>* const inner_class_list = inner_classes();
1994 if (inner_class_list == NULL) {
1995 return 0;
1996 }
1997 const int length = inner_class_list->length();
1998 if (length % inner_class_next_offset == 0) {
1999 return 0;
2000 }
2001 const int index = length - enclosing_method_attribute_size;
2002 assert(offset < enclosing_method_attribute_size, "invalid offset");
2003 return inner_class_list->at(index + offset);
2004 }
2005
2006 void InstanceKlass::set_enclosing_method_indices(u2 class_index,
2007 u2 method_index) {
2008 Array<jushort>* inner_class_list = inner_classes();
2009 assert (inner_class_list != NULL, "_inner_classes list is not set up");
2010 int length = inner_class_list->length();
2011 if (length % inner_class_next_offset == enclosing_method_attribute_size) {
2012 int index = length - enclosing_method_attribute_size;
2013 inner_class_list->at_put(
2014 index + enclosing_method_class_index_offset, class_index);
2015 inner_class_list->at_put(
2016 index + enclosing_method_method_index_offset, method_index);
2017 }
2018 }
2019
2020 // Lookup or create a jmethodID.
2021 // This code is called by the VMThread and JavaThreads so the
2022 // locking has to be done very carefully to avoid deadlocks
2023 // and/or other cache consistency problems.
2024 //
2025 jmethodID InstanceKlass::get_jmethod_id(const methodHandle& method_h) {
2026 size_t idnum = (size_t)method_h->method_idnum();
2027 jmethodID* jmeths = methods_jmethod_ids_acquire();
2028 size_t length = 0;
2029 jmethodID id = NULL;
2030
2031 // We use a double-check locking idiom here because this cache is
2032 // performance sensitive. In the normal system, this cache only
2033 // transitions from NULL to non-NULL which is safe because we use
2034 // release_set_methods_jmethod_ids() to advertise the new cache.
2035 // A partially constructed cache should never be seen by a racing
2036 // thread. We also use release_store() to save a new jmethodID
2037 // in the cache so a partially constructed jmethodID should never be
2038 // seen either. Cache reads of existing jmethodIDs proceed without a
2039 // lock, but cache writes of a new jmethodID requires uniqueness and
2040 // creation of the cache itself requires no leaks so a lock is
2041 // generally acquired in those two cases.
2042 //
2043 // If the RedefineClasses() API has been used, then this cache can
2044 // grow and we'll have transitions from non-NULL to bigger non-NULL.
2045 // Cache creation requires no leaks and we require safety between all
2046 // cache accesses and freeing of the old cache so a lock is generally
2047 // acquired when the RedefineClasses() API has been used.
2048
2049 if (jmeths != NULL) {
2050 // the cache already exists
2051 if (!idnum_can_increment()) {
2052 // the cache can't grow so we can just get the current values
2053 get_jmethod_id_length_value(jmeths, idnum, &length, &id);
2054 } else {
2055 // cache can grow so we have to be more careful
2056 if (Threads::number_of_threads() == 0 ||
2057 SafepointSynchronize::is_at_safepoint()) {
2058 // we're single threaded or at a safepoint - no locking needed
2059 get_jmethod_id_length_value(jmeths, idnum, &length, &id);
2060 } else {
2061 MutexLocker ml(JmethodIdCreation_lock, Mutex::_no_safepoint_check_flag);
2062 get_jmethod_id_length_value(jmeths, idnum, &length, &id);
2063 }
2064 }
2065 }
2066 // implied else:
2067 // we need to allocate a cache so default length and id values are good
2068
2069 if (jmeths == NULL || // no cache yet
2070 length <= idnum || // cache is too short
2071 id == NULL) { // cache doesn't contain entry
2072
2073 // This function can be called by the VMThread so we have to do all
2074 // things that might block on a safepoint before grabbing the lock.
2075 // Otherwise, we can deadlock with the VMThread or have a cache
2076 // consistency issue. These vars keep track of what we might have
2077 // to free after the lock is dropped.
2078 jmethodID to_dealloc_id = NULL;
2079 jmethodID* to_dealloc_jmeths = NULL;
2080
2081 // may not allocate new_jmeths or use it if we allocate it
2082 jmethodID* new_jmeths = NULL;
2083 if (length <= idnum) {
2084 // allocate a new cache that might be used
2085 size_t size = MAX2(idnum+1, (size_t)idnum_allocated_count());
2086 new_jmeths = NEW_C_HEAP_ARRAY(jmethodID, size+1, mtClass);
2087 memset(new_jmeths, 0, (size+1)*sizeof(jmethodID));
2088 // cache size is stored in element[0], other elements offset by one
2089 new_jmeths[0] = (jmethodID)size;
2090 }
2091
2092 // allocate a new jmethodID that might be used
2093 jmethodID new_id = NULL;
2094 if (method_h->is_old() && !method_h->is_obsolete()) {
2095 // The method passed in is old (but not obsolete), we need to use the current version
2096 Method* current_method = method_with_idnum((int)idnum);
2097 assert(current_method != NULL, "old and but not obsolete, so should exist");
2098 new_id = Method::make_jmethod_id(class_loader_data(), current_method);
2099 } else {
2100 // It is the current version of the method or an obsolete method,
2101 // use the version passed in
2102 new_id = Method::make_jmethod_id(class_loader_data(), method_h());
2103 }
2104
2105 if (Threads::number_of_threads() == 0 ||
2106 SafepointSynchronize::is_at_safepoint()) {
2107 // we're single threaded or at a safepoint - no locking needed
2108 id = get_jmethod_id_fetch_or_update(idnum, new_id, new_jmeths,
2109 &to_dealloc_id, &to_dealloc_jmeths);
2110 } else {
2111 MutexLocker ml(JmethodIdCreation_lock, Mutex::_no_safepoint_check_flag);
2112 id = get_jmethod_id_fetch_or_update(idnum, new_id, new_jmeths,
2113 &to_dealloc_id, &to_dealloc_jmeths);
2114 }
2115
2116 // The lock has been dropped so we can free resources.
2117 // Free up either the old cache or the new cache if we allocated one.
2118 if (to_dealloc_jmeths != NULL) {
2119 FreeHeap(to_dealloc_jmeths);
2120 }
2121 // free up the new ID since it wasn't needed
2122 if (to_dealloc_id != NULL) {
2123 Method::destroy_jmethod_id(class_loader_data(), to_dealloc_id);
2124 }
2125 }
2126 return id;
2127 }
2128
2129 // Figure out how many jmethodIDs haven't been allocated, and make
2130 // sure space for them is pre-allocated. This makes getting all
2131 // method ids much, much faster with classes with more than 8
2132 // methods, and has a *substantial* effect on performance with jvmti
2133 // code that loads all jmethodIDs for all classes.
2134 void InstanceKlass::ensure_space_for_methodids(int start_offset) {
2135 int new_jmeths = 0;
2136 int length = methods()->length();
2137 for (int index = start_offset; index < length; index++) {
2138 Method* m = methods()->at(index);
2139 jmethodID id = m->find_jmethod_id_or_null();
2140 if (id == NULL) {
2141 new_jmeths++;
2142 }
2143 }
2144 if (new_jmeths != 0) {
2145 Method::ensure_jmethod_ids(class_loader_data(), new_jmeths);
2146 }
2147 }
2148
2149 // Common code to fetch the jmethodID from the cache or update the
2150 // cache with the new jmethodID. This function should never do anything
2151 // that causes the caller to go to a safepoint or we can deadlock with
2152 // the VMThread or have cache consistency issues.
2153 //
2154 jmethodID InstanceKlass::get_jmethod_id_fetch_or_update(
2155 size_t idnum, jmethodID new_id,
2156 jmethodID* new_jmeths, jmethodID* to_dealloc_id_p,
2157 jmethodID** to_dealloc_jmeths_p) {
2158 assert(new_id != NULL, "sanity check");
2159 assert(to_dealloc_id_p != NULL, "sanity check");
2160 assert(to_dealloc_jmeths_p != NULL, "sanity check");
2161 assert(Threads::number_of_threads() == 0 ||
2162 SafepointSynchronize::is_at_safepoint() ||
2163 JmethodIdCreation_lock->owned_by_self(), "sanity check");
2164
2165 // reacquire the cache - we are locked, single threaded or at a safepoint
2166 jmethodID* jmeths = methods_jmethod_ids_acquire();
2167 jmethodID id = NULL;
2168 size_t length = 0;
2169
2170 if (jmeths == NULL || // no cache yet
2171 (length = (size_t)jmeths[0]) <= idnum) { // cache is too short
2172 if (jmeths != NULL) {
2173 // copy any existing entries from the old cache
2174 for (size_t index = 0; index < length; index++) {
2175 new_jmeths[index+1] = jmeths[index+1];
2176 }
2177 *to_dealloc_jmeths_p = jmeths; // save old cache for later delete
2178 }
2179 release_set_methods_jmethod_ids(jmeths = new_jmeths);
2180 } else {
2181 // fetch jmethodID (if any) from the existing cache
2182 id = jmeths[idnum+1];
2183 *to_dealloc_jmeths_p = new_jmeths; // save new cache for later delete
2184 }
2185 if (id == NULL) {
2186 // No matching jmethodID in the existing cache or we have a new
2187 // cache or we just grew the cache. This cache write is done here
2188 // by the first thread to win the foot race because a jmethodID
2189 // needs to be unique once it is generally available.
2190 id = new_id;
2191
2192 // The jmethodID cache can be read while unlocked so we have to
2193 // make sure the new jmethodID is complete before installing it
2194 // in the cache.
2195 Atomic::release_store(&jmeths[idnum+1], id);
2196 } else {
2197 *to_dealloc_id_p = new_id; // save new id for later delete
2198 }
2199 return id;
2200 }
2201
2202
2203 // Common code to get the jmethodID cache length and the jmethodID
2204 // value at index idnum if there is one.
2205 //
2206 void InstanceKlass::get_jmethod_id_length_value(jmethodID* cache,
2207 size_t idnum, size_t *length_p, jmethodID* id_p) {
2208 assert(cache != NULL, "sanity check");
2209 assert(length_p != NULL, "sanity check");
2210 assert(id_p != NULL, "sanity check");
2211
2212 // cache size is stored in element[0], other elements offset by one
2213 *length_p = (size_t)cache[0];
2214 if (*length_p <= idnum) { // cache is too short
2215 *id_p = NULL;
2216 } else {
2217 *id_p = cache[idnum+1]; // fetch jmethodID (if any)
2218 }
2219 }
2220
2221
2222 // Lookup a jmethodID, NULL if not found. Do no blocking, no allocations, no handles
2223 jmethodID InstanceKlass::jmethod_id_or_null(Method* method) {
2224 size_t idnum = (size_t)method->method_idnum();
2225 jmethodID* jmeths = methods_jmethod_ids_acquire();
2226 size_t length; // length assigned as debugging crumb
2227 jmethodID id = NULL;
2228 if (jmeths != NULL && // If there is a cache
2229 (length = (size_t)jmeths[0]) > idnum) { // and if it is long enough,
2230 id = jmeths[idnum+1]; // Look up the id (may be NULL)
2231 }
2232 return id;
2233 }
2234
2235 inline DependencyContext InstanceKlass::dependencies() {
2236 DependencyContext dep_context(&_dep_context, &_dep_context_last_cleaned);
2237 return dep_context;
2238 }
2239
2240 int InstanceKlass::mark_dependent_nmethods(KlassDepChange& changes) {
2241 return dependencies().mark_dependent_nmethods(changes);
2242 }
2243
2244 void InstanceKlass::add_dependent_nmethod(nmethod* nm) {
2245 dependencies().add_dependent_nmethod(nm);
2246 }
2247
2248 void InstanceKlass::remove_dependent_nmethod(nmethod* nm) {
2249 dependencies().remove_dependent_nmethod(nm);
2250 }
2251
2252 void InstanceKlass::clean_dependency_context() {
2253 dependencies().clean_unloading_dependents();
2254 }
2255
2256 #ifndef PRODUCT
2257 void InstanceKlass::print_dependent_nmethods(bool verbose) {
2258 dependencies().print_dependent_nmethods(verbose);
2259 }
2260
2261 bool InstanceKlass::is_dependent_nmethod(nmethod* nm) {
2262 return dependencies().is_dependent_nmethod(nm);
2263 }
2264 #endif //PRODUCT
2265
2266 void InstanceKlass::clean_weak_instanceklass_links() {
2267 clean_implementors_list();
2268 clean_method_data();
2269 }
2270
2271 void InstanceKlass::clean_implementors_list() {
2272 assert(is_loader_alive(), "this klass should be live");
2273 if (is_interface()) {
2274 assert (ClassUnloading, "only called for ClassUnloading");
2275 for (;;) {
2276 // Use load_acquire due to competing with inserts
2277 Klass* impl = Atomic::load_acquire(adr_implementor());
2278 if (impl != NULL && !impl->is_loader_alive()) {
2279 // NULL this field, might be an unloaded klass or NULL
2280 Klass* volatile* klass = adr_implementor();
2281 if (Atomic::cmpxchg(klass, impl, (Klass*)NULL) == impl) {
2282 // Successfully unlinking implementor.
2283 if (log_is_enabled(Trace, class, unload)) {
2284 ResourceMark rm;
2285 log_trace(class, unload)("unlinking class (implementor): %s", impl->external_name());
2286 }
2287 return;
2288 }
2289 } else {
2290 return;
2291 }
2292 }
2293 }
2294 }
2295
2296 void InstanceKlass::clean_method_data() {
2297 for (int m = 0; m < methods()->length(); m++) {
2298 MethodData* mdo = methods()->at(m)->method_data();
2299 if (mdo != NULL) {
2300 MutexLocker ml(SafepointSynchronize::is_at_safepoint() ? NULL : mdo->extra_data_lock());
2301 mdo->clean_method_data(/*always_clean*/false);
2302 }
2303 }
2304 }
2305
2306 bool InstanceKlass::supers_have_passed_fingerprint_checks() {
2307 if (java_super() != NULL && !java_super()->has_passed_fingerprint_check()) {
2308 ResourceMark rm;
2309 log_trace(class, fingerprint)("%s : super %s not fingerprinted", external_name(), java_super()->external_name());
2310 return false;
2311 }
2312
2313 Array<InstanceKlass*>* local_interfaces = this->local_interfaces();
2314 if (local_interfaces != NULL) {
2315 int length = local_interfaces->length();
2316 for (int i = 0; i < length; i++) {
2317 InstanceKlass* intf = local_interfaces->at(i);
2318 if (!intf->has_passed_fingerprint_check()) {
2319 ResourceMark rm;
2320 log_trace(class, fingerprint)("%s : interface %s not fingerprinted", external_name(), intf->external_name());
2321 return false;
2322 }
2323 }
2324 }
2325
2326 return true;
2327 }
2328
2329 bool InstanceKlass::should_store_fingerprint(bool is_hidden_or_anonymous) {
2330 #if INCLUDE_AOT
2331 // We store the fingerprint into the InstanceKlass only in the following 2 cases:
2332 if (CalculateClassFingerprint) {
2333 // (1) We are running AOT to generate a shared library.
2334 return true;
2335 }
2336 if (Arguments::is_dumping_archive()) {
2337 // (2) We are running -Xshare:dump or -XX:ArchiveClassesAtExit to create a shared archive
2338 return true;
2339 }
2340 if (UseAOT && is_hidden_or_anonymous) {
2341 // (3) We are using AOT code from a shared library and see a hidden or unsafe anonymous class
2342 return true;
2343 }
2344 #endif
2345
2346 // In all other cases we might set the _misc_has_passed_fingerprint_check bit,
2347 // but do not store the 64-bit fingerprint to save space.
2348 return false;
2349 }
2350
2351 bool InstanceKlass::has_stored_fingerprint() const {
2352 #if INCLUDE_AOT
2353 return should_store_fingerprint() || is_shared();
2354 #else
2355 return false;
2356 #endif
2357 }
2358
2359 uint64_t InstanceKlass::get_stored_fingerprint() const {
2360 address adr = adr_fingerprint();
2361 if (adr != NULL) {
2362 return (uint64_t)Bytes::get_native_u8(adr); // adr may not be 64-bit aligned
2363 }
2364 return 0;
2365 }
2366
2367 void InstanceKlass::store_fingerprint(uint64_t fingerprint) {
2368 address adr = adr_fingerprint();
2369 if (adr != NULL) {
2370 Bytes::put_native_u8(adr, (u8)fingerprint); // adr may not be 64-bit aligned
2371
2372 ResourceMark rm;
2373 log_trace(class, fingerprint)("stored as " PTR64_FORMAT " for class %s", fingerprint, external_name());
2374 }
2375 }
2376
2377 void InstanceKlass::metaspace_pointers_do(MetaspaceClosure* it) {
2378 Klass::metaspace_pointers_do(it);
2379
2380 if (log_is_enabled(Trace, cds)) {
2381 ResourceMark rm;
2382 log_trace(cds)("Iter(InstanceKlass): %p (%s)", this, external_name());
2383 }
2384
2385 it->push(&_annotations);
2386 it->push((Klass**)&_array_klasses);
2387 it->push(&_constants);
2388 it->push(&_inner_classes);
2389 it->push(&_array_name);
2390 #if INCLUDE_JVMTI
2391 it->push(&_previous_versions);
2392 #endif
2393 it->push(&_methods);
2394 it->push(&_default_methods);
2395 it->push(&_local_interfaces);
2396 it->push(&_transitive_interfaces);
2397 it->push(&_method_ordering);
2398 it->push(&_default_vtable_indices);
2399 it->push(&_fields);
2400
2401 if (itable_length() > 0) {
2402 itableOffsetEntry* ioe = (itableOffsetEntry*)start_of_itable();
2403 int method_table_offset_in_words = ioe->offset()/wordSize;
2404 int nof_interfaces = (method_table_offset_in_words - itable_offset_in_words())
2405 / itableOffsetEntry::size();
2406
2407 for (int i = 0; i < nof_interfaces; i ++, ioe ++) {
2408 if (ioe->interface_klass() != NULL) {
2409 it->push(ioe->interface_klass_addr());
2410 itableMethodEntry* ime = ioe->first_method_entry(this);
2411 int n = klassItable::method_count_for_interface(ioe->interface_klass());
2412 for (int index = 0; index < n; index ++) {
2413 it->push(ime[index].method_addr());
2414 }
2415 }
2416 }
2417 }
2418
2419 it->push(&_nest_members);
2420 it->push(&_record_components);
2421 }
2422
2423 void InstanceKlass::remove_unshareable_info() {
2424 Klass::remove_unshareable_info();
2425
2426 if (SystemDictionaryShared::has_class_failed_verification(this)) {
2427 // Classes are attempted to link during dumping and may fail,
2428 // but these classes are still in the dictionary and class list in CLD.
2429 // If the class has failed verification, there is nothing else to remove.
2430 return;
2431 }
2432
2433 // Reset to the 'allocated' state to prevent any premature accessing to
2434 // a shared class at runtime while the class is still being loaded and
2435 // restored. A class' init_state is set to 'loaded' at runtime when it's
2436 // being added to class hierarchy (see SystemDictionary:::add_to_hierarchy()).
2437 _init_state = allocated;
2438
2439 { // Otherwise this needs to take out the Compile_lock.
2440 assert(SafepointSynchronize::is_at_safepoint(), "only called at safepoint");
2441 init_implementor();
2442 }
2443
2444 constants()->remove_unshareable_info();
2445
2446 for (int i = 0; i < methods()->length(); i++) {
2447 Method* m = methods()->at(i);
2448 m->remove_unshareable_info();
2449 }
2450
2451 // do array classes also.
2452 if (array_klasses() != NULL) {
2453 array_klasses()->remove_unshareable_info();
2454 }
2455
2456 // These are not allocated from metaspace. They are safe to set to NULL.
2457 _source_debug_extension = NULL;
2458 _dep_context = NULL;
2459 _osr_nmethods_head = NULL;
2460 #if INCLUDE_JVMTI
2461 _breakpoints = NULL;
2462 _previous_versions = NULL;
2463 _cached_class_file = NULL;
2464 _jvmti_cached_class_field_map = NULL;
2465 #endif
2466
2467 _init_thread = NULL;
2468 _methods_jmethod_ids = NULL;
2469 _jni_ids = NULL;
2470 _oop_map_cache = NULL;
2471 // clear _nest_host to ensure re-load at runtime
2472 _nest_host = NULL;
2473 _package_entry = NULL;
2474 _dep_context_last_cleaned = 0;
2475 }
2476
2477 void InstanceKlass::remove_java_mirror() {
2478 Klass::remove_java_mirror();
2479
2480 // do array classes also.
2481 if (array_klasses() != NULL) {
2482 array_klasses()->remove_java_mirror();
2483 }
2484 }
2485
2486 void InstanceKlass::restore_unshareable_info(ClassLoaderData* loader_data, Handle protection_domain,
2487 PackageEntry* pkg_entry, TRAPS) {
2488 // SystemDictionary::add_to_hierarchy() sets the init_state to loaded
2489 // before the InstanceKlass is added to the SystemDictionary. Make
2490 // sure the current state is <loaded.
2491 assert(!is_loaded(), "invalid init state");
2492 set_package(loader_data, pkg_entry, CHECK);
2493 Klass::restore_unshareable_info(loader_data, protection_domain, CHECK);
2494
2495 Array<Method*>* methods = this->methods();
2496 int num_methods = methods->length();
2497 for (int index = 0; index < num_methods; ++index) {
2498 methods->at(index)->restore_unshareable_info(CHECK);
2499 }
2500 if (JvmtiExport::has_redefined_a_class()) {
2501 // Reinitialize vtable because RedefineClasses may have changed some
2502 // entries in this vtable for super classes so the CDS vtable might
2503 // point to old or obsolete entries. RedefineClasses doesn't fix up
2504 // vtables in the shared system dictionary, only the main one.
2505 // It also redefines the itable too so fix that too.
2506 vtable().initialize_vtable(false, CHECK);
2507 itable().initialize_itable(false, CHECK);
2508 }
2509
2510 // restore constant pool resolved references
2511 constants()->restore_unshareable_info(CHECK);
2512
2513 if (array_klasses() != NULL) {
2514 // Array classes have null protection domain.
2515 // --> see ArrayKlass::complete_create_array_klass()
2516 ArrayKlass::cast(array_klasses())->restore_unshareable_info(ClassLoaderData::the_null_class_loader_data(), Handle(), CHECK);
2517 }
2518
2519 // Initialize current biased locking state.
2520 if (UseBiasedLocking && BiasedLocking::enabled()) {
2521 set_prototype_header(markWord::biased_locking_prototype());
2522 }
2523 }
2524
2525 void InstanceKlass::set_shared_class_loader_type(s2 loader_type) {
2526 switch (loader_type) {
2527 case ClassLoader::BOOT_LOADER:
2528 _misc_flags |= _misc_is_shared_boot_class;
2529 break;
2530 case ClassLoader::PLATFORM_LOADER:
2531 _misc_flags |= _misc_is_shared_platform_class;
2532 break;
2533 case ClassLoader::APP_LOADER:
2534 _misc_flags |= _misc_is_shared_app_class;
2535 break;
2536 default:
2537 ShouldNotReachHere();
2538 break;
2539 }
2540 }
2541
2542 #if INCLUDE_JVMTI
2543 static void clear_all_breakpoints(Method* m) {
2544 m->clear_all_breakpoints();
2545 }
2546 #endif
2547
2548 void InstanceKlass::unload_class(InstanceKlass* ik) {
2549 // Release dependencies.
2550 ik->dependencies().remove_all_dependents();
2551
2552 // notify the debugger
2553 if (JvmtiExport::should_post_class_unload()) {
2554 JvmtiExport::post_class_unload(ik);
2555 }
2556
2557 // notify ClassLoadingService of class unload
2558 ClassLoadingService::notify_class_unloaded(ik);
2559
2560 if (Arguments::is_dumping_archive()) {
2561 SystemDictionaryShared::remove_dumptime_info(ik);
2562 }
2563
2564 if (log_is_enabled(Info, class, unload)) {
2565 ResourceMark rm;
2566 log_info(class, unload)("unloading class %s " INTPTR_FORMAT, ik->external_name(), p2i(ik));
2567 }
2568
2569 Events::log_class_unloading(Thread::current(), ik);
2570
2571 #if INCLUDE_JFR
2572 assert(ik != NULL, "invariant");
2573 EventClassUnload event;
2574 event.set_unloadedClass(ik);
2575 event.set_definingClassLoader(ik->class_loader_data());
2576 event.commit();
2577 #endif
2578 }
2579
2580 static void method_release_C_heap_structures(Method* m) {
2581 m->release_C_heap_structures();
2582 }
2583
2584 void InstanceKlass::release_C_heap_structures(InstanceKlass* ik) {
2585 // Clean up C heap
2586 ik->release_C_heap_structures();
2587 ik->constants()->release_C_heap_structures();
2588
2589 // Deallocate and call destructors for MDO mutexes
2590 ik->methods_do(method_release_C_heap_structures);
2591
2592 }
2593
2594 void InstanceKlass::release_C_heap_structures() {
2595 // Can't release the constant pool here because the constant pool can be
2596 // deallocated separately from the InstanceKlass for default methods and
2597 // redefine classes.
2598
2599 // Deallocate oop map cache
2600 if (_oop_map_cache != NULL) {
2601 delete _oop_map_cache;
2602 _oop_map_cache = NULL;
2603 }
2604
2605 // Deallocate JNI identifiers for jfieldIDs
2606 JNIid::deallocate(jni_ids());
2607 set_jni_ids(NULL);
2608
2609 jmethodID* jmeths = methods_jmethod_ids_acquire();
2610 if (jmeths != (jmethodID*)NULL) {
2611 release_set_methods_jmethod_ids(NULL);
2612 FreeHeap(jmeths);
2613 }
2614
2615 assert(_dep_context == NULL,
2616 "dependencies should already be cleaned");
2617
2618 #if INCLUDE_JVMTI
2619 // Deallocate breakpoint records
2620 if (breakpoints() != 0x0) {
2621 methods_do(clear_all_breakpoints);
2622 assert(breakpoints() == 0x0, "should have cleared breakpoints");
2623 }
2624
2625 // deallocate the cached class file
2626 if (_cached_class_file != NULL) {
2627 os::free(_cached_class_file);
2628 _cached_class_file = NULL;
2629 }
2630 #endif
2631
2632 // Decrement symbol reference counts associated with the unloaded class.
2633 if (_name != NULL) _name->decrement_refcount();
2634
2635 // unreference array name derived from this class name (arrays of an unloaded
2636 // class can't be referenced anymore).
2637 if (_array_name != NULL) _array_name->decrement_refcount();
2638 FREE_C_HEAP_ARRAY(char, _source_debug_extension);
2639 }
2640
2641 void InstanceKlass::set_source_debug_extension(const char* array, int length) {
2642 if (array == NULL) {
2643 _source_debug_extension = NULL;
2644 } else {
2645 // Adding one to the attribute length in order to store a null terminator
2646 // character could cause an overflow because the attribute length is
2647 // already coded with an u4 in the classfile, but in practice, it's
2648 // unlikely to happen.
2649 assert((length+1) > length, "Overflow checking");
2650 char* sde = NEW_C_HEAP_ARRAY(char, (length + 1), mtClass);
2651 for (int i = 0; i < length; i++) {
2652 sde[i] = array[i];
2653 }
2654 sde[length] = '\0';
2655 _source_debug_extension = sde;
2656 }
2657 }
2658
2659 const char* InstanceKlass::signature_name() const {
2660 int hash_len = 0;
2661 char hash_buf[40];
2662
2663 // If this is an unsafe anonymous class, append a hash to make the name unique
2664 if (is_unsafe_anonymous()) {
2665 intptr_t hash = (java_mirror() != NULL) ? java_mirror()->identity_hash() : 0;
2666 jio_snprintf(hash_buf, sizeof(hash_buf), "/" UINTX_FORMAT, (uintx)hash);
2667 hash_len = (int)strlen(hash_buf);
2668 }
2669
2670 // Get the internal name as a c string
2671 const char* src = (const char*) (name()->as_C_string());
2672 const int src_length = (int)strlen(src);
2673
2674 char* dest = NEW_RESOURCE_ARRAY(char, src_length + hash_len + 3);
2675
2676 // Add L as type indicator
2677 int dest_index = 0;
2678 dest[dest_index++] = JVM_SIGNATURE_CLASS;
2679
2680 // Add the actual class name
2681 for (int src_index = 0; src_index < src_length; ) {
2682 dest[dest_index++] = src[src_index++];
2683 }
2684
2685 if (is_hidden()) {
2686 int end_class = -1;
2687 for (int index = (int)dest_index-1; index > 0; index--) { // dest[0] is "L"
2688 dest[index+1] = dest[index];
2689 if (dest[index] == '+') {
2690 // Replace the last '+' with a ';' followed with '/'.
2691 dest[index] = JVM_SIGNATURE_ENDCLASS;
2692 dest[index+1] = JVM_SIGNATURE_SLASH;
2693 end_class = index;
2694 break;
2695 }
2696 }
2697 assert(end_class > 0, "unexpected hidden class name");
2698 dest_index++;
2699 }
2700
2701 // If we have a hash, append it
2702 for (int hash_index = 0; hash_index < hash_len; ) {
2703 dest[dest_index++] = hash_buf[hash_index++];
2704 }
2705
2706 // Add the semicolon and the NULL
2707 if (!is_hidden()) {
2708 dest[dest_index++] = JVM_SIGNATURE_ENDCLASS;
2709 }
2710 dest[dest_index] = '\0';
2711 return dest;
2712 }
2713
2714 ModuleEntry* InstanceKlass::module() const {
2715 // For an unsafe anonymous class return the host class' module
2716 if (is_unsafe_anonymous()) {
2717 assert(unsafe_anonymous_host() != NULL, "unsafe anonymous class must have a host class");
2718 return unsafe_anonymous_host()->module();
2719 }
2720
2721 if (is_hidden() &&
2722 in_unnamed_package() &&
2723 class_loader_data()->has_class_mirror_holder()) {
2724 // For a non-strong hidden class defined to an unnamed package,
2725 // its (class held) CLD will not have an unnamed module created for it.
2726 // Two choices to find the correct ModuleEntry:
2727 // 1. If hidden class is within a nest, use nest host's module
2728 // 2. Find the unnamed module off from the class loader
2729 // For now option #2 is used since a nest host is not set until
2730 // after the instance class is created in jvm_lookup_define_class().
2731 if (class_loader_data()->is_boot_class_loader_data()) {
2732 return ClassLoaderData::the_null_class_loader_data()->unnamed_module();
2733 } else {
2734 oop module = java_lang_ClassLoader::unnamedModule(class_loader_data()->class_loader());
2735 assert(java_lang_Module::is_instance(module), "Not an instance of java.lang.Module");
2736 return java_lang_Module::module_entry(module);
2737 }
2738 }
2739
2740 // Class is in a named package
2741 if (!in_unnamed_package()) {
2742 return _package_entry->module();
2743 }
2744
2745 // Class is in an unnamed package, return its loader's unnamed module
2746 return class_loader_data()->unnamed_module();
2747 }
2748
2749 void InstanceKlass::set_package(ClassLoaderData* loader_data, PackageEntry* pkg_entry, TRAPS) {
2750
2751 // ensure java/ packages only loaded by boot or platform builtin loaders
2752 check_prohibited_package(name(), loader_data, CHECK);
2753
2754 TempNewSymbol pkg_name = pkg_entry != NULL ? pkg_entry->name() : ClassLoader::package_from_class_name(name());
2755
2756 if (pkg_name != NULL && loader_data != NULL) {
2757
2758 // Find in class loader's package entry table.
2759 _package_entry = pkg_entry != NULL ? pkg_entry : loader_data->packages()->lookup_only(pkg_name);
2760
2761 // If the package name is not found in the loader's package
2762 // entry table, it is an indication that the package has not
2763 // been defined. Consider it defined within the unnamed module.
2764 if (_package_entry == NULL) {
2765
2766 if (!ModuleEntryTable::javabase_defined()) {
2767 // Before java.base is defined during bootstrapping, define all packages in
2768 // the java.base module. If a non-java.base package is erroneously placed
2769 // in the java.base module it will be caught later when java.base
2770 // is defined by ModuleEntryTable::verify_javabase_packages check.
2771 assert(ModuleEntryTable::javabase_moduleEntry() != NULL, JAVA_BASE_NAME " module is NULL");
2772 _package_entry = loader_data->packages()->lookup(pkg_name, ModuleEntryTable::javabase_moduleEntry());
2773 } else {
2774 assert(loader_data->unnamed_module() != NULL, "unnamed module is NULL");
2775 _package_entry = loader_data->packages()->lookup(pkg_name,
2776 loader_data->unnamed_module());
2777 }
2778
2779 // A package should have been successfully created
2780 DEBUG_ONLY(ResourceMark rm(THREAD));
2781 assert(_package_entry != NULL, "Package entry for class %s not found, loader %s",
2782 name()->as_C_string(), loader_data->loader_name_and_id());
2783 }
2784
2785 if (log_is_enabled(Debug, module)) {
2786 ResourceMark rm(THREAD);
2787 ModuleEntry* m = _package_entry->module();
2788 log_trace(module)("Setting package: class: %s, package: %s, loader: %s, module: %s",
2789 external_name(),
2790 pkg_name->as_C_string(),
2791 loader_data->loader_name_and_id(),
2792 (m->is_named() ? m->name()->as_C_string() : UNNAMED_MODULE));
2793 }
2794 } else {
2795 ResourceMark rm(THREAD);
2796 log_trace(module)("Setting package: class: %s, package: unnamed, loader: %s, module: %s",
2797 external_name(),
2798 (loader_data != NULL) ? loader_data->loader_name_and_id() : "NULL",
2799 UNNAMED_MODULE);
2800 }
2801 }
2802
2803
2804 // different versions of is_same_class_package
2805
2806 bool InstanceKlass::is_same_class_package(const Klass* class2) const {
2807 oop classloader1 = this->class_loader();
2808 PackageEntry* classpkg1 = this->package();
2809 if (class2->is_objArray_klass()) {
2810 class2 = ObjArrayKlass::cast(class2)->bottom_klass();
2811 }
2812
2813 oop classloader2;
2814 PackageEntry* classpkg2;
2815 if (class2->is_instance_klass()) {
2816 classloader2 = class2->class_loader();
2817 classpkg2 = class2->package();
2818 } else {
2819 assert(class2->is_typeArray_klass(), "should be type array");
2820 classloader2 = NULL;
2821 classpkg2 = NULL;
2822 }
2823
2824 // Same package is determined by comparing class loader
2825 // and package entries. Both must be the same. This rule
2826 // applies even to classes that are defined in the unnamed
2827 // package, they still must have the same class loader.
2828 if ((classloader1 == classloader2) && (classpkg1 == classpkg2)) {
2829 return true;
2830 }
2831
2832 return false;
2833 }
2834
2835 // return true if this class and other_class are in the same package. Classloader
2836 // and classname information is enough to determine a class's package
2837 bool InstanceKlass::is_same_class_package(oop other_class_loader,
2838 const Symbol* other_class_name) const {
2839 if (class_loader() != other_class_loader) {
2840 return false;
2841 }
2842 if (name()->fast_compare(other_class_name) == 0) {
2843 return true;
2844 }
2845
2846 {
2847 ResourceMark rm;
2848
2849 bool bad_class_name = false;
2850 TempNewSymbol other_pkg = ClassLoader::package_from_class_name(other_class_name, &bad_class_name);
2851 if (bad_class_name) {
2852 return false;
2853 }
2854 // Check that package_from_class_name() returns NULL, not "", if there is no package.
2855 assert(other_pkg == NULL || other_pkg->utf8_length() > 0, "package name is empty string");
2856
2857 const Symbol* const this_package_name =
2858 this->package() != NULL ? this->package()->name() : NULL;
2859
2860 if (this_package_name == NULL || other_pkg == NULL) {
2861 // One of the two doesn't have a package. Only return true if the other
2862 // one also doesn't have a package.
2863 return this_package_name == other_pkg;
2864 }
2865
2866 // Check if package is identical
2867 return this_package_name->fast_compare(other_pkg) == 0;
2868 }
2869 }
2870
2871 // Returns true iff super_method can be overridden by a method in targetclassname
2872 // See JLS 3rd edition 8.4.6.1
2873 // Assumes name-signature match
2874 // "this" is InstanceKlass of super_method which must exist
2875 // note that the InstanceKlass of the method in the targetclassname has not always been created yet
2876 bool InstanceKlass::is_override(const methodHandle& super_method, Handle targetclassloader, Symbol* targetclassname, TRAPS) {
2877 // Private methods can not be overridden
2878 if (super_method->is_private()) {
2879 return false;
2880 }
2881 // If super method is accessible, then override
2882 if ((super_method->is_protected()) ||
2883 (super_method->is_public())) {
2884 return true;
2885 }
2886 // Package-private methods are not inherited outside of package
2887 assert(super_method->is_package_private(), "must be package private");
2888 return(is_same_class_package(targetclassloader(), targetclassname));
2889 }
2890
2891 // Only boot and platform class loaders can define classes in "java/" packages.
2892 void InstanceKlass::check_prohibited_package(Symbol* class_name,
2893 ClassLoaderData* loader_data,
2894 TRAPS) {
2895 if (!loader_data->is_boot_class_loader_data() &&
2896 !loader_data->is_platform_class_loader_data() &&
2897 class_name != NULL) {
2898 ResourceMark rm(THREAD);
2899 char* name = class_name->as_C_string();
2900 if (strncmp(name, JAVAPKG, JAVAPKG_LEN) == 0 && name[JAVAPKG_LEN] == '/') {
2901 TempNewSymbol pkg_name = ClassLoader::package_from_class_name(class_name);
2902 assert(pkg_name != NULL, "Error in parsing package name starting with 'java/'");
2903 name = pkg_name->as_C_string();
2904 const char* class_loader_name = loader_data->loader_name_and_id();
2905 StringUtils::replace_no_expand(name, "/", ".");
2906 const char* msg_text1 = "Class loader (instance of): ";
2907 const char* msg_text2 = " tried to load prohibited package name: ";
2908 size_t len = strlen(msg_text1) + strlen(class_loader_name) + strlen(msg_text2) + strlen(name) + 1;
2909 char* message = NEW_RESOURCE_ARRAY_IN_THREAD(THREAD, char, len);
2910 jio_snprintf(message, len, "%s%s%s%s", msg_text1, class_loader_name, msg_text2, name);
2911 THROW_MSG(vmSymbols::java_lang_SecurityException(), message);
2912 }
2913 }
2914 return;
2915 }
2916
2917 bool InstanceKlass::find_inner_classes_attr(int* ooff, int* noff, TRAPS) const {
2918 constantPoolHandle i_cp(THREAD, constants());
2919 for (InnerClassesIterator iter(this); !iter.done(); iter.next()) {
2920 int ioff = iter.inner_class_info_index();
2921 if (ioff != 0) {
2922 // Check to see if the name matches the class we're looking for
2923 // before attempting to find the class.
2924 if (i_cp->klass_name_at_matches(this, ioff)) {
2925 Klass* inner_klass = i_cp->klass_at(ioff, CHECK_false);
2926 if (this == inner_klass) {
2927 *ooff = iter.outer_class_info_index();
2928 *noff = iter.inner_name_index();
2929 return true;
2930 }
2931 }
2932 }
2933 }
2934 return false;
2935 }
2936
2937 InstanceKlass* InstanceKlass::compute_enclosing_class(bool* inner_is_member, TRAPS) const {
2938 InstanceKlass* outer_klass = NULL;
2939 *inner_is_member = false;
2940 int ooff = 0, noff = 0;
2941 bool has_inner_classes_attr = find_inner_classes_attr(&ooff, &noff, THREAD);
2942 if (has_inner_classes_attr) {
2943 constantPoolHandle i_cp(THREAD, constants());
2944 if (ooff != 0) {
2945 Klass* ok = i_cp->klass_at(ooff, CHECK_NULL);
2946 outer_klass = InstanceKlass::cast(ok);
2947 *inner_is_member = true;
2948 }
2949 if (NULL == outer_klass) {
2950 // It may be a local or anonymous class; try for that.
2951 int encl_method_class_idx = enclosing_method_class_index();
2952 if (encl_method_class_idx != 0) {
2953 Klass* ok = i_cp->klass_at(encl_method_class_idx, CHECK_NULL);
2954 outer_klass = InstanceKlass::cast(ok);
2955 *inner_is_member = false;
2956 }
2957 }
2958 }
2959
2960 // If no inner class attribute found for this class.
2961 if (NULL == outer_klass) return NULL;
2962
2963 // Throws an exception if outer klass has not declared k as an inner klass
2964 // We need evidence that each klass knows about the other, or else
2965 // the system could allow a spoof of an inner class to gain access rights.
2966 Reflection::check_for_inner_class(outer_klass, this, *inner_is_member, CHECK_NULL);
2967 return outer_klass;
2968 }
2969
2970 jint InstanceKlass::compute_modifier_flags(TRAPS) const {
2971 jint access = access_flags().as_int();
2972
2973 // But check if it happens to be member class.
2974 InnerClassesIterator iter(this);
2975 for (; !iter.done(); iter.next()) {
2976 int ioff = iter.inner_class_info_index();
2977 // Inner class attribute can be zero, skip it.
2978 // Strange but true: JVM spec. allows null inner class refs.
2979 if (ioff == 0) continue;
2980
2981 // only look at classes that are already loaded
2982 // since we are looking for the flags for our self.
2983 Symbol* inner_name = constants()->klass_name_at(ioff);
2984 if (name() == inner_name) {
2985 // This is really a member class.
2986 access = iter.inner_access_flags();
2987 break;
2988 }
2989 }
2990 // Remember to strip ACC_SUPER bit
2991 return (access & (~JVM_ACC_SUPER)) & JVM_ACC_WRITTEN_FLAGS;
2992 }
2993
2994 jint InstanceKlass::jvmti_class_status() const {
2995 jint result = 0;
2996
2997 if (is_linked()) {
2998 result |= JVMTI_CLASS_STATUS_VERIFIED | JVMTI_CLASS_STATUS_PREPARED;
2999 }
3000
3001 if (is_initialized()) {
3002 assert(is_linked(), "Class status is not consistent");
3003 result |= JVMTI_CLASS_STATUS_INITIALIZED;
3004 }
3005 if (is_in_error_state()) {
3006 result |= JVMTI_CLASS_STATUS_ERROR;
3007 }
3008 return result;
3009 }
3010
3011 Method* InstanceKlass::method_at_itable(Klass* holder, int index, TRAPS) {
3012 itableOffsetEntry* ioe = (itableOffsetEntry*)start_of_itable();
3013 int method_table_offset_in_words = ioe->offset()/wordSize;
3014 int nof_interfaces = (method_table_offset_in_words - itable_offset_in_words())
3015 / itableOffsetEntry::size();
3016
3017 for (int cnt = 0 ; ; cnt ++, ioe ++) {
3018 // If the interface isn't implemented by the receiver class,
3019 // the VM should throw IncompatibleClassChangeError.
3020 if (cnt >= nof_interfaces) {
3021 ResourceMark rm(THREAD);
3022 stringStream ss;
3023 bool same_module = (module() == holder->module());
3024 ss.print("Receiver class %s does not implement "
3025 "the interface %s defining the method to be called "
3026 "(%s%s%s)",
3027 external_name(), holder->external_name(),
3028 (same_module) ? joint_in_module_of_loader(holder) : class_in_module_of_loader(),
3029 (same_module) ? "" : "; ",
3030 (same_module) ? "" : holder->class_in_module_of_loader());
3031 THROW_MSG_NULL(vmSymbols::java_lang_IncompatibleClassChangeError(), ss.as_string());
3032 }
3033
3034 Klass* ik = ioe->interface_klass();
3035 if (ik == holder) break;
3036 }
3037
3038 itableMethodEntry* ime = ioe->first_method_entry(this);
3039 Method* m = ime[index].method();
3040 if (m == NULL) {
3041 THROW_NULL(vmSymbols::java_lang_AbstractMethodError());
3042 }
3043 return m;
3044 }
3045
3046
3047 #if INCLUDE_JVMTI
3048 // update default_methods for redefineclasses for methods that are
3049 // not yet in the vtable due to concurrent subclass define and superinterface
3050 // redefinition
3051 // Note: those in the vtable, should have been updated via adjust_method_entries
3052 void InstanceKlass::adjust_default_methods(bool* trace_name_printed) {
3053 // search the default_methods for uses of either obsolete or EMCP methods
3054 if (default_methods() != NULL) {
3055 for (int index = 0; index < default_methods()->length(); index ++) {
3056 Method* old_method = default_methods()->at(index);
3057 if (old_method == NULL || !old_method->is_old()) {
3058 continue; // skip uninteresting entries
3059 }
3060 assert(!old_method->is_deleted(), "default methods may not be deleted");
3061 Method* new_method = old_method->get_new_method();
3062 default_methods()->at_put(index, new_method);
3063
3064 if (log_is_enabled(Info, redefine, class, update)) {
3065 ResourceMark rm;
3066 if (!(*trace_name_printed)) {
3067 log_info(redefine, class, update)
3068 ("adjust: klassname=%s default methods from name=%s",
3069 external_name(), old_method->method_holder()->external_name());
3070 *trace_name_printed = true;
3071 }
3072 log_debug(redefine, class, update, vtables)
3073 ("default method update: %s(%s) ",
3074 new_method->name()->as_C_string(), new_method->signature()->as_C_string());
3075 }
3076 }
3077 }
3078 }
3079 #endif // INCLUDE_JVMTI
3080
3081 // On-stack replacement stuff
3082 void InstanceKlass::add_osr_nmethod(nmethod* n) {
3083 assert_lock_strong(CompiledMethod_lock);
3084 #ifndef PRODUCT
3085 if (TieredCompilation) {
3086 nmethod * prev = lookup_osr_nmethod(n->method(), n->osr_entry_bci(), n->comp_level(), true);
3087 assert(prev == NULL || !prev->is_in_use(),
3088 "redundunt OSR recompilation detected. memory leak in CodeCache!");
3089 }
3090 #endif
3091 // only one compilation can be active
3092 {
3093 assert(n->is_osr_method(), "wrong kind of nmethod");
3094 n->set_osr_link(osr_nmethods_head());
3095 set_osr_nmethods_head(n);
3096 // Raise the highest osr level if necessary
3097 if (TieredCompilation) {
3098 Method* m = n->method();
3099 m->set_highest_osr_comp_level(MAX2(m->highest_osr_comp_level(), n->comp_level()));
3100 }
3101 }
3102
3103 // Get rid of the osr methods for the same bci that have lower levels.
3104 if (TieredCompilation) {
3105 for (int l = CompLevel_limited_profile; l < n->comp_level(); l++) {
3106 nmethod *inv = lookup_osr_nmethod(n->method(), n->osr_entry_bci(), l, true);
3107 if (inv != NULL && inv->is_in_use()) {
3108 inv->make_not_entrant();
3109 }
3110 }
3111 }
3112 }
3113
3114 // Remove osr nmethod from the list. Return true if found and removed.
3115 bool InstanceKlass::remove_osr_nmethod(nmethod* n) {
3116 // This is a short non-blocking critical region, so the no safepoint check is ok.
3117 MutexLocker ml(CompiledMethod_lock->owned_by_self() ? NULL : CompiledMethod_lock
3118 , Mutex::_no_safepoint_check_flag);
3119 assert(n->is_osr_method(), "wrong kind of nmethod");
3120 nmethod* last = NULL;
3121 nmethod* cur = osr_nmethods_head();
3122 int max_level = CompLevel_none; // Find the max comp level excluding n
3123 Method* m = n->method();
3124 // Search for match
3125 bool found = false;
3126 while(cur != NULL && cur != n) {
3127 if (TieredCompilation && m == cur->method()) {
3128 // Find max level before n
3129 max_level = MAX2(max_level, cur->comp_level());
3130 }
3131 last = cur;
3132 cur = cur->osr_link();
3133 }
3134 nmethod* next = NULL;
3135 if (cur == n) {
3136 found = true;
3137 next = cur->osr_link();
3138 if (last == NULL) {
3139 // Remove first element
3140 set_osr_nmethods_head(next);
3141 } else {
3142 last->set_osr_link(next);
3143 }
3144 }
3145 n->set_osr_link(NULL);
3146 if (TieredCompilation) {
3147 cur = next;
3148 while (cur != NULL) {
3149 // Find max level after n
3150 if (m == cur->method()) {
3151 max_level = MAX2(max_level, cur->comp_level());
3152 }
3153 cur = cur->osr_link();
3154 }
3155 m->set_highest_osr_comp_level(max_level);
3156 }
3157 return found;
3158 }
3159
3160 int InstanceKlass::mark_osr_nmethods(const Method* m) {
3161 MutexLocker ml(CompiledMethod_lock->owned_by_self() ? NULL : CompiledMethod_lock,
3162 Mutex::_no_safepoint_check_flag);
3163 nmethod* osr = osr_nmethods_head();
3164 int found = 0;
3165 while (osr != NULL) {
3166 assert(osr->is_osr_method(), "wrong kind of nmethod found in chain");
3167 if (osr->method() == m) {
3168 osr->mark_for_deoptimization();
3169 found++;
3170 }
3171 osr = osr->osr_link();
3172 }
3173 return found;
3174 }
3175
3176 nmethod* InstanceKlass::lookup_osr_nmethod(const Method* m, int bci, int comp_level, bool match_level) const {
3177 MutexLocker ml(CompiledMethod_lock->owned_by_self() ? NULL : CompiledMethod_lock,
3178 Mutex::_no_safepoint_check_flag);
3179 nmethod* osr = osr_nmethods_head();
3180 nmethod* best = NULL;
3181 while (osr != NULL) {
3182 assert(osr->is_osr_method(), "wrong kind of nmethod found in chain");
3183 // There can be a time when a c1 osr method exists but we are waiting
3184 // for a c2 version. When c2 completes its osr nmethod we will trash
3185 // the c1 version and only be able to find the c2 version. However
3186 // while we overflow in the c1 code at back branches we don't want to
3187 // try and switch to the same code as we are already running
3188
3189 if (osr->method() == m &&
3190 (bci == InvocationEntryBci || osr->osr_entry_bci() == bci)) {
3191 if (match_level) {
3192 if (osr->comp_level() == comp_level) {
3193 // Found a match - return it.
3194 return osr;
3195 }
3196 } else {
3197 if (best == NULL || (osr->comp_level() > best->comp_level())) {
3198 if (osr->comp_level() == CompLevel_highest_tier) {
3199 // Found the best possible - return it.
3200 return osr;
3201 }
3202 best = osr;
3203 }
3204 }
3205 }
3206 osr = osr->osr_link();
3207 }
3208
3209 assert(match_level == false || best == NULL, "shouldn't pick up anything if match_level is set");
3210 if (best != NULL && best->comp_level() >= comp_level) {
3211 return best;
3212 }
3213 return NULL;
3214 }
3215
3216 // -----------------------------------------------------------------------------------------------------
3217 // Printing
3218
3219 #ifndef PRODUCT
3220
3221 #define BULLET " - "
3222
3223 static const char* state_names[] = {
3224 "allocated", "loaded", "linked", "being_initialized", "fully_initialized", "initialization_error"
3225 };
3226
3227 static void print_vtable(intptr_t* start, int len, outputStream* st) {
3228 for (int i = 0; i < len; i++) {
3229 intptr_t e = start[i];
3230 st->print("%d : " INTPTR_FORMAT, i, e);
3231 if (MetaspaceObj::is_valid((Metadata*)e)) {
3232 st->print(" ");
3233 ((Metadata*)e)->print_value_on(st);
3234 }
3235 st->cr();
3236 }
3237 }
3238
3239 static void print_vtable(vtableEntry* start, int len, outputStream* st) {
3240 return print_vtable(reinterpret_cast<intptr_t*>(start), len, st);
3241 }
3242
3243 void InstanceKlass::print_on(outputStream* st) const {
3244 assert(is_klass(), "must be klass");
3245 Klass::print_on(st);
3246
3247 st->print(BULLET"instance size: %d", size_helper()); st->cr();
3248 st->print(BULLET"klass size: %d", size()); st->cr();
3249 st->print(BULLET"access: "); access_flags().print_on(st); st->cr();
3250 st->print(BULLET"state: "); st->print_cr("%s", state_names[_init_state]);
3251 st->print(BULLET"name: "); name()->print_value_on(st); st->cr();
3252 st->print(BULLET"super: "); Metadata::print_value_on_maybe_null(st, super()); st->cr();
3253 st->print(BULLET"sub: ");
3254 Klass* sub = subklass();
3255 int n;
3256 for (n = 0; sub != NULL; n++, sub = sub->next_sibling()) {
3257 if (n < MaxSubklassPrintSize) {
3258 sub->print_value_on(st);
3259 st->print(" ");
3260 }
3261 }
3262 if (n >= MaxSubklassPrintSize) st->print("(" INTX_FORMAT " more klasses...)", n - MaxSubklassPrintSize);
3263 st->cr();
3264
3265 if (is_interface()) {
3266 st->print_cr(BULLET"nof implementors: %d", nof_implementors());
3267 if (nof_implementors() == 1) {
3268 st->print_cr(BULLET"implementor: ");
3269 st->print(" ");
3270 implementor()->print_value_on(st);
3271 st->cr();
3272 }
3273 }
3274
3275 st->print(BULLET"arrays: "); Metadata::print_value_on_maybe_null(st, array_klasses()); st->cr();
3276 st->print(BULLET"methods: "); methods()->print_value_on(st); st->cr();
3277 if (Verbose || WizardMode) {
3278 Array<Method*>* method_array = methods();
3279 for (int i = 0; i < method_array->length(); i++) {
3280 st->print("%d : ", i); method_array->at(i)->print_value(); st->cr();
3281 }
3282 }
3283 st->print(BULLET"method ordering: "); method_ordering()->print_value_on(st); st->cr();
3284 st->print(BULLET"default_methods: "); default_methods()->print_value_on(st); st->cr();
3285 if (Verbose && default_methods() != NULL) {
3286 Array<Method*>* method_array = default_methods();
3287 for (int i = 0; i < method_array->length(); i++) {
3288 st->print("%d : ", i); method_array->at(i)->print_value(); st->cr();
3289 }
3290 }
3291 if (default_vtable_indices() != NULL) {
3292 st->print(BULLET"default vtable indices: "); default_vtable_indices()->print_value_on(st); st->cr();
3293 }
3294 st->print(BULLET"local interfaces: "); local_interfaces()->print_value_on(st); st->cr();
3295 st->print(BULLET"trans. interfaces: "); transitive_interfaces()->print_value_on(st); st->cr();
3296 st->print(BULLET"constants: "); constants()->print_value_on(st); st->cr();
3297 if (class_loader_data() != NULL) {
3298 st->print(BULLET"class loader data: ");
3299 class_loader_data()->print_value_on(st);
3300 st->cr();
3301 }
3302 st->print(BULLET"unsafe anonymous host class: "); Metadata::print_value_on_maybe_null(st, unsafe_anonymous_host()); st->cr();
3303 if (source_file_name() != NULL) {
3304 st->print(BULLET"source file: ");
3305 source_file_name()->print_value_on(st);
3306 st->cr();
3307 }
3308 if (source_debug_extension() != NULL) {
3309 st->print(BULLET"source debug extension: ");
3310 st->print("%s", source_debug_extension());
3311 st->cr();
3312 }
3313 st->print(BULLET"class annotations: "); class_annotations()->print_value_on(st); st->cr();
3314 st->print(BULLET"class type annotations: "); class_type_annotations()->print_value_on(st); st->cr();
3315 st->print(BULLET"field annotations: "); fields_annotations()->print_value_on(st); st->cr();
3316 st->print(BULLET"field type annotations: "); fields_type_annotations()->print_value_on(st); st->cr();
3317 {
3318 bool have_pv = false;
3319 // previous versions are linked together through the InstanceKlass
3320 for (InstanceKlass* pv_node = previous_versions();
3321 pv_node != NULL;
3322 pv_node = pv_node->previous_versions()) {
3323 if (!have_pv)
3324 st->print(BULLET"previous version: ");
3325 have_pv = true;
3326 pv_node->constants()->print_value_on(st);
3327 }
3328 if (have_pv) st->cr();
3329 }
3330
3331 if (generic_signature() != NULL) {
3332 st->print(BULLET"generic signature: ");
3333 generic_signature()->print_value_on(st);
3334 st->cr();
3335 }
3336 st->print(BULLET"inner classes: "); inner_classes()->print_value_on(st); st->cr();
3337 st->print(BULLET"nest members: "); nest_members()->print_value_on(st); st->cr();
3338 if (record_components() != NULL) {
3339 st->print(BULLET"record components: "); record_components()->print_value_on(st); st->cr();
3340 }
3341 if (java_mirror() != NULL) {
3342 st->print(BULLET"java mirror: ");
3343 java_mirror()->print_value_on(st);
3344 st->cr();
3345 } else {
3346 st->print_cr(BULLET"java mirror: NULL");
3347 }
3348 st->print(BULLET"vtable length %d (start addr: " INTPTR_FORMAT ")", vtable_length(), p2i(start_of_vtable())); st->cr();
3349 if (vtable_length() > 0 && (Verbose || WizardMode)) print_vtable(start_of_vtable(), vtable_length(), st);
3350 st->print(BULLET"itable length %d (start addr: " INTPTR_FORMAT ")", itable_length(), p2i(start_of_itable())); st->cr();
3351 if (itable_length() > 0 && (Verbose || WizardMode)) print_vtable(start_of_itable(), itable_length(), st);
3352 st->print_cr(BULLET"---- static fields (%d words):", static_field_size());
3353 FieldPrinter print_static_field(st);
3354 ((InstanceKlass*)this)->do_local_static_fields(&print_static_field);
3355 st->print_cr(BULLET"---- non-static fields (%d words):", nonstatic_field_size());
3356 FieldPrinter print_nonstatic_field(st);
3357 InstanceKlass* ik = const_cast<InstanceKlass*>(this);
3358 ik->do_nonstatic_fields(&print_nonstatic_field);
3359
3360 st->print(BULLET"non-static oop maps: ");
3361 OopMapBlock* map = start_of_nonstatic_oop_maps();
3362 OopMapBlock* end_map = map + nonstatic_oop_map_count();
3363 while (map < end_map) {
3364 st->print("%d-%d ", map->offset(), map->offset() + heapOopSize*(map->count() - 1));
3365 map++;
3366 }
3367 st->cr();
3368 }
3369
3370 #endif //PRODUCT
3371
3372 void InstanceKlass::print_value_on(outputStream* st) const {
3373 assert(is_klass(), "must be klass");
3374 if (Verbose || WizardMode) access_flags().print_on(st);
3375 name()->print_value_on(st);
3376 }
3377
3378 #ifndef PRODUCT
3379
3380 void FieldPrinter::do_field(fieldDescriptor* fd) {
3381 _st->print(BULLET);
3382 if (_obj == NULL) {
3383 fd->print_on(_st);
3384 _st->cr();
3385 } else {
3386 fd->print_on_for(_st, _obj);
3387 _st->cr();
3388 }
3389 }
3390
3391
3392 void InstanceKlass::oop_print_on(oop obj, outputStream* st) {
3393 Klass::oop_print_on(obj, st);
3394
3395 if (this == SystemDictionary::String_klass()) {
3396 typeArrayOop value = java_lang_String::value(obj);
3397 juint length = java_lang_String::length(obj);
3398 if (value != NULL &&
3399 value->is_typeArray() &&
3400 length <= (juint) value->length()) {
3401 st->print(BULLET"string: ");
3402 java_lang_String::print(obj, st);
3403 st->cr();
3404 if (!WizardMode) return; // that is enough
3405 }
3406 }
3407
3408 st->print_cr(BULLET"---- fields (total size %d words):", oop_size(obj));
3409 FieldPrinter print_field(st, obj);
3410 do_nonstatic_fields(&print_field);
3411
3412 if (this == SystemDictionary::Class_klass()) {
3413 st->print(BULLET"signature: ");
3414 java_lang_Class::print_signature(obj, st);
3415 st->cr();
3416 Klass* mirrored_klass = java_lang_Class::as_Klass(obj);
3417 st->print(BULLET"fake entry for mirror: ");
3418 Metadata::print_value_on_maybe_null(st, mirrored_klass);
3419 st->cr();
3420 Klass* array_klass = java_lang_Class::array_klass_acquire(obj);
3421 st->print(BULLET"fake entry for array: ");
3422 Metadata::print_value_on_maybe_null(st, array_klass);
3423 st->cr();
3424 st->print_cr(BULLET"fake entry for oop_size: %d", java_lang_Class::oop_size(obj));
3425 st->print_cr(BULLET"fake entry for static_oop_field_count: %d", java_lang_Class::static_oop_field_count(obj));
3426 Klass* real_klass = java_lang_Class::as_Klass(obj);
3427 if (real_klass != NULL && real_klass->is_instance_klass()) {
3428 InstanceKlass::cast(real_klass)->do_local_static_fields(&print_field);
3429 }
3430 } else if (this == SystemDictionary::MethodType_klass()) {
3431 st->print(BULLET"signature: ");
3432 java_lang_invoke_MethodType::print_signature(obj, st);
3433 st->cr();
3434 }
3435 }
3436
3437 bool InstanceKlass::verify_itable_index(int i) {
3438 int method_count = klassItable::method_count_for_interface(this);
3439 assert(i >= 0 && i < method_count, "index out of bounds");
3440 return true;
3441 }
3442
3443 #endif //PRODUCT
3444
3445 void InstanceKlass::oop_print_value_on(oop obj, outputStream* st) {
3446 st->print("a ");
3447 name()->print_value_on(st);
3448 obj->print_address_on(st);
3449 if (this == SystemDictionary::String_klass()
3450 && java_lang_String::value(obj) != NULL) {
3451 ResourceMark rm;
3452 int len = java_lang_String::length(obj);
3453 int plen = (len < 24 ? len : 12);
3454 char* str = java_lang_String::as_utf8_string(obj, 0, plen);
3455 st->print(" = \"%s\"", str);
3456 if (len > plen)
3457 st->print("...[%d]", len);
3458 } else if (this == SystemDictionary::Class_klass()) {
3459 Klass* k = java_lang_Class::as_Klass(obj);
3460 st->print(" = ");
3461 if (k != NULL) {
3462 k->print_value_on(st);
3463 } else {
3464 const char* tname = type2name(java_lang_Class::primitive_type(obj));
3465 st->print("%s", tname ? tname : "type?");
3466 }
3467 } else if (this == SystemDictionary::MethodType_klass()) {
3468 st->print(" = ");
3469 java_lang_invoke_MethodType::print_signature(obj, st);
3470 } else if (java_lang_boxing_object::is_instance(obj)) {
3471 st->print(" = ");
3472 java_lang_boxing_object::print(obj, st);
3473 } else if (this == SystemDictionary::LambdaForm_klass()) {
3474 oop vmentry = java_lang_invoke_LambdaForm::vmentry(obj);
3475 if (vmentry != NULL) {
3476 st->print(" => ");
3477 vmentry->print_value_on(st);
3478 }
3479 } else if (this == SystemDictionary::MemberName_klass()) {
3480 Metadata* vmtarget = java_lang_invoke_MemberName::vmtarget(obj);
3481 if (vmtarget != NULL) {
3482 st->print(" = ");
3483 vmtarget->print_value_on(st);
3484 } else {
3485 java_lang_invoke_MemberName::clazz(obj)->print_value_on(st);
3486 st->print(".");
3487 java_lang_invoke_MemberName::name(obj)->print_value_on(st);
3488 }
3489 }
3490 }
3491
3492 const char* InstanceKlass::internal_name() const {
3493 return external_name();
3494 }
3495
3496 void InstanceKlass::print_class_load_logging(ClassLoaderData* loader_data,
3497 const char* module_name,
3498 const ClassFileStream* cfs) const {
3499 if (!log_is_enabled(Info, class, load)) {
3500 return;
3501 }
3502
3503 ResourceMark rm;
3504 LogMessage(class, load) msg;
3505 stringStream info_stream;
3506
3507 // Name and class hierarchy info
3508 info_stream.print("%s", external_name());
3509
3510 // Source
3511 if (cfs != NULL) {
3512 if (cfs->source() != NULL) {
3513 if (module_name != NULL) {
3514 // When the boot loader created the stream, it didn't know the module name
3515 // yet. Let's format it now.
3516 if (cfs->from_boot_loader_modules_image()) {
3517 info_stream.print(" source: jrt:/%s", module_name);
3518 } else {
3519 info_stream.print(" source: %s", cfs->source());
3520 }
3521 } else {
3522 info_stream.print(" source: %s", cfs->source());
3523 }
3524 } else if (loader_data == ClassLoaderData::the_null_class_loader_data()) {
3525 Thread* THREAD = Thread::current();
3526 Klass* caller =
3527 THREAD->is_Java_thread()
3528 ? ((JavaThread*)THREAD)->security_get_caller_class(1)
3529 : NULL;
3530 // caller can be NULL, for example, during a JVMTI VM_Init hook
3531 if (caller != NULL) {
3532 info_stream.print(" source: instance of %s", caller->external_name());
3533 } else {
3534 // source is unknown
3535 }
3536 } else {
3537 oop class_loader = loader_data->class_loader();
3538 info_stream.print(" source: %s", class_loader->klass()->external_name());
3539 }
3540 } else {
3541 assert(this->is_shared(), "must be");
3542 if (MetaspaceShared::is_shared_dynamic((void*)this)) {
3543 info_stream.print(" source: shared objects file (top)");
3544 } else {
3545 info_stream.print(" source: shared objects file");
3546 }
3547 }
3548
3549 msg.info("%s", info_stream.as_string());
3550
3551 if (log_is_enabled(Debug, class, load)) {
3552 stringStream debug_stream;
3553
3554 // Class hierarchy info
3555 debug_stream.print(" klass: " INTPTR_FORMAT " super: " INTPTR_FORMAT,
3556 p2i(this), p2i(superklass()));
3557
3558 // Interfaces
3559 if (local_interfaces() != NULL && local_interfaces()->length() > 0) {
3560 debug_stream.print(" interfaces:");
3561 int length = local_interfaces()->length();
3562 for (int i = 0; i < length; i++) {
3563 debug_stream.print(" " INTPTR_FORMAT,
3564 p2i(InstanceKlass::cast(local_interfaces()->at(i))));
3565 }
3566 }
3567
3568 // Class loader
3569 debug_stream.print(" loader: [");
3570 loader_data->print_value_on(&debug_stream);
3571 debug_stream.print("]");
3572
3573 // Classfile checksum
3574 if (cfs) {
3575 debug_stream.print(" bytes: %d checksum: %08x",
3576 cfs->length(),
3577 ClassLoader::crc32(0, (const char*)cfs->buffer(),
3578 cfs->length()));
3579 }
3580
3581 msg.debug("%s", debug_stream.as_string());
3582 }
3583 }
3584
3585 // Verification
3586
3587 class VerifyFieldClosure: public BasicOopIterateClosure {
3588 protected:
3589 template <class T> void do_oop_work(T* p) {
3590 oop obj = RawAccess<>::oop_load(p);
3591 if (!oopDesc::is_oop_or_null(obj)) {
3592 tty->print_cr("Failed: " PTR_FORMAT " -> " PTR_FORMAT, p2i(p), p2i(obj));
3593 Universe::print_on(tty);
3594 guarantee(false, "boom");
3595 }
3596 }
3597 public:
3598 virtual void do_oop(oop* p) { VerifyFieldClosure::do_oop_work(p); }
3599 virtual void do_oop(narrowOop* p) { VerifyFieldClosure::do_oop_work(p); }
3600 };
3601
3602 void InstanceKlass::verify_on(outputStream* st) {
3603 #ifndef PRODUCT
3604 // Avoid redundant verifies, this really should be in product.
3605 if (_verify_count == Universe::verify_count()) return;
3606 _verify_count = Universe::verify_count();
3607 #endif
3608
3609 // Verify Klass
3610 Klass::verify_on(st);
3611
3612 // Verify that klass is present in ClassLoaderData
3613 guarantee(class_loader_data()->contains_klass(this),
3614 "this class isn't found in class loader data");
3615
3616 // Verify vtables
3617 if (is_linked()) {
3618 // $$$ This used to be done only for m/s collections. Doing it
3619 // always seemed a valid generalization. (DLD -- 6/00)
3620 vtable().verify(st);
3621 }
3622
3623 // Verify first subklass
3624 if (subklass() != NULL) {
3625 guarantee(subklass()->is_klass(), "should be klass");
3626 }
3627
3628 // Verify siblings
3629 Klass* super = this->super();
3630 Klass* sib = next_sibling();
3631 if (sib != NULL) {
3632 if (sib == this) {
3633 fatal("subclass points to itself " PTR_FORMAT, p2i(sib));
3634 }
3635
3636 guarantee(sib->is_klass(), "should be klass");
3637 guarantee(sib->super() == super, "siblings should have same superklass");
3638 }
3639
3640 // Verify local interfaces
3641 if (local_interfaces()) {
3642 Array<InstanceKlass*>* local_interfaces = this->local_interfaces();
3643 for (int j = 0; j < local_interfaces->length(); j++) {
3644 InstanceKlass* e = local_interfaces->at(j);
3645 guarantee(e->is_klass() && e->is_interface(), "invalid local interface");
3646 }
3647 }
3648
3649 // Verify transitive interfaces
3650 if (transitive_interfaces() != NULL) {
3651 Array<InstanceKlass*>* transitive_interfaces = this->transitive_interfaces();
3652 for (int j = 0; j < transitive_interfaces->length(); j++) {
3653 InstanceKlass* e = transitive_interfaces->at(j);
3654 guarantee(e->is_klass() && e->is_interface(), "invalid transitive interface");
3655 }
3656 }
3657
3658 // Verify methods
3659 if (methods() != NULL) {
3660 Array<Method*>* methods = this->methods();
3661 for (int j = 0; j < methods->length(); j++) {
3662 guarantee(methods->at(j)->is_method(), "non-method in methods array");
3663 }
3664 for (int j = 0; j < methods->length() - 1; j++) {
3665 Method* m1 = methods->at(j);
3666 Method* m2 = methods->at(j + 1);
3667 guarantee(m1->name()->fast_compare(m2->name()) <= 0, "methods not sorted correctly");
3668 }
3669 }
3670
3671 // Verify method ordering
3672 if (method_ordering() != NULL) {
3673 Array<int>* method_ordering = this->method_ordering();
3674 int length = method_ordering->length();
3675 if (JvmtiExport::can_maintain_original_method_order() ||
3676 ((UseSharedSpaces || Arguments::is_dumping_archive()) && length != 0)) {
3677 guarantee(length == methods()->length(), "invalid method ordering length");
3678 jlong sum = 0;
3679 for (int j = 0; j < length; j++) {
3680 int original_index = method_ordering->at(j);
3681 guarantee(original_index >= 0, "invalid method ordering index");
3682 guarantee(original_index < length, "invalid method ordering index");
3683 sum += original_index;
3684 }
3685 // Verify sum of indices 0,1,...,length-1
3686 guarantee(sum == ((jlong)length*(length-1))/2, "invalid method ordering sum");
3687 } else {
3688 guarantee(length == 0, "invalid method ordering length");
3689 }
3690 }
3691
3692 // Verify default methods
3693 if (default_methods() != NULL) {
3694 Array<Method*>* methods = this->default_methods();
3695 for (int j = 0; j < methods->length(); j++) {
3696 guarantee(methods->at(j)->is_method(), "non-method in methods array");
3697 }
3698 for (int j = 0; j < methods->length() - 1; j++) {
3699 Method* m1 = methods->at(j);
3700 Method* m2 = methods->at(j + 1);
3701 guarantee(m1->name()->fast_compare(m2->name()) <= 0, "methods not sorted correctly");
3702 }
3703 }
3704
3705 // Verify JNI static field identifiers
3706 if (jni_ids() != NULL) {
3707 jni_ids()->verify(this);
3708 }
3709
3710 // Verify other fields
3711 if (array_klasses() != NULL) {
3712 guarantee(array_klasses()->is_klass(), "should be klass");
3713 }
3714 if (constants() != NULL) {
3715 guarantee(constants()->is_constantPool(), "should be constant pool");
3716 }
3717 const Klass* anonymous_host = unsafe_anonymous_host();
3718 if (anonymous_host != NULL) {
3719 guarantee(anonymous_host->is_klass(), "should be klass");
3720 }
3721 }
3722
3723 void InstanceKlass::oop_verify_on(oop obj, outputStream* st) {
3724 Klass::oop_verify_on(obj, st);
3725 VerifyFieldClosure blk;
3726 obj->oop_iterate(&blk);
3727 }
3728
3729
3730 // JNIid class for jfieldIDs only
3731 // Note to reviewers:
3732 // These JNI functions are just moved over to column 1 and not changed
3733 // in the compressed oops workspace.
3734 JNIid::JNIid(Klass* holder, int offset, JNIid* next) {
3735 _holder = holder;
3736 _offset = offset;
3737 _next = next;
3738 debug_only(_is_static_field_id = false;)
3739 }
3740
3741
3742 JNIid* JNIid::find(int offset) {
3743 JNIid* current = this;
3744 while (current != NULL) {
3745 if (current->offset() == offset) return current;
3746 current = current->next();
3747 }
3748 return NULL;
3749 }
3750
3751 void JNIid::deallocate(JNIid* current) {
3752 while (current != NULL) {
3753 JNIid* next = current->next();
3754 delete current;
3755 current = next;
3756 }
3757 }
3758
3759
3760 void JNIid::verify(Klass* holder) {
3761 int first_field_offset = InstanceMirrorKlass::offset_of_static_fields();
3762 int end_field_offset;
3763 end_field_offset = first_field_offset + (InstanceKlass::cast(holder)->static_field_size() * wordSize);
3764
3765 JNIid* current = this;
3766 while (current != NULL) {
3767 guarantee(current->holder() == holder, "Invalid klass in JNIid");
3768 #ifdef ASSERT
3769 int o = current->offset();
3770 if (current->is_static_field_id()) {
3771 guarantee(o >= first_field_offset && o < end_field_offset, "Invalid static field offset in JNIid");
3772 }
3773 #endif
3774 current = current->next();
3775 }
3776 }
3777
3778 void InstanceKlass::set_init_state(ClassState state) {
3779 #ifdef ASSERT
3780 bool good_state = is_shared() ? (_init_state <= state)
3781 : (_init_state < state);
3782 assert(good_state || state == allocated, "illegal state transition");
3783 #endif
3784 assert(_init_thread == NULL, "should be cleared before state change");
3785 _init_state = (u1)state;
3786 }
3787
3788 #if INCLUDE_JVMTI
3789
3790 // RedefineClasses() support for previous versions
3791
3792 // Globally, there is at least one previous version of a class to walk
3793 // during class unloading, which is saved because old methods in the class
3794 // are still running. Otherwise the previous version list is cleaned up.
3795 bool InstanceKlass::_has_previous_versions = false;
3796
3797 // Returns true if there are previous versions of a class for class
3798 // unloading only. Also resets the flag to false. purge_previous_version
3799 // will set the flag to true if there are any left, i.e., if there's any
3800 // work to do for next time. This is to avoid the expensive code cache
3801 // walk in CLDG::clean_deallocate_lists().
3802 bool InstanceKlass::has_previous_versions_and_reset() {
3803 bool ret = _has_previous_versions;
3804 log_trace(redefine, class, iklass, purge)("Class unloading: has_previous_versions = %s",
3805 ret ? "true" : "false");
3806 _has_previous_versions = false;
3807 return ret;
3808 }
3809
3810 // Purge previous versions before adding new previous versions of the class and
3811 // during class unloading.
3812 void InstanceKlass::purge_previous_version_list() {
3813 assert(SafepointSynchronize::is_at_safepoint(), "only called at safepoint");
3814 assert(has_been_redefined(), "Should only be called for main class");
3815
3816 // Quick exit.
3817 if (previous_versions() == NULL) {
3818 return;
3819 }
3820
3821 // This klass has previous versions so see what we can cleanup
3822 // while it is safe to do so.
3823
3824 int deleted_count = 0; // leave debugging breadcrumbs
3825 int live_count = 0;
3826 ClassLoaderData* loader_data = class_loader_data();
3827 assert(loader_data != NULL, "should never be null");
3828
3829 ResourceMark rm;
3830 log_trace(redefine, class, iklass, purge)("%s: previous versions", external_name());
3831
3832 // previous versions are linked together through the InstanceKlass
3833 InstanceKlass* pv_node = previous_versions();
3834 InstanceKlass* last = this;
3835 int version = 0;
3836
3837 // check the previous versions list
3838 for (; pv_node != NULL; ) {
3839
3840 ConstantPool* pvcp = pv_node->constants();
3841 assert(pvcp != NULL, "cp ref was unexpectedly cleared");
3842
3843 if (!pvcp->on_stack()) {
3844 // If the constant pool isn't on stack, none of the methods
3845 // are executing. Unlink this previous_version.
3846 // The previous version InstanceKlass is on the ClassLoaderData deallocate list
3847 // so will be deallocated during the next phase of class unloading.
3848 log_trace(redefine, class, iklass, purge)
3849 ("previous version " INTPTR_FORMAT " is dead.", p2i(pv_node));
3850 // For debugging purposes.
3851 pv_node->set_is_scratch_class();
3852 // Unlink from previous version list.
3853 assert(pv_node->class_loader_data() == loader_data, "wrong loader_data");
3854 InstanceKlass* next = pv_node->previous_versions();
3855 pv_node->link_previous_versions(NULL); // point next to NULL
3856 last->link_previous_versions(next);
3857 // Add to the deallocate list after unlinking
3858 loader_data->add_to_deallocate_list(pv_node);
3859 pv_node = next;
3860 deleted_count++;
3861 version++;
3862 continue;
3863 } else {
3864 log_trace(redefine, class, iklass, purge)("previous version " INTPTR_FORMAT " is alive", p2i(pv_node));
3865 assert(pvcp->pool_holder() != NULL, "Constant pool with no holder");
3866 guarantee (!loader_data->is_unloading(), "unloaded classes can't be on the stack");
3867 live_count++;
3868 // found a previous version for next time we do class unloading
3869 _has_previous_versions = true;
3870 }
3871
3872 // At least one method is live in this previous version.
3873 // Reset dead EMCP methods not to get breakpoints.
3874 // All methods are deallocated when all of the methods for this class are no
3875 // longer running.
3876 Array<Method*>* method_refs = pv_node->methods();
3877 if (method_refs != NULL) {
3878 log_trace(redefine, class, iklass, purge)("previous methods length=%d", method_refs->length());
3879 for (int j = 0; j < method_refs->length(); j++) {
3880 Method* method = method_refs->at(j);
3881
3882 if (!method->on_stack()) {
3883 // no breakpoints for non-running methods
3884 if (method->is_running_emcp()) {
3885 method->set_running_emcp(false);
3886 }
3887 } else {
3888 assert (method->is_obsolete() || method->is_running_emcp(),
3889 "emcp method cannot run after emcp bit is cleared");
3890 log_trace(redefine, class, iklass, purge)
3891 ("purge: %s(%s): prev method @%d in version @%d is alive",
3892 method->name()->as_C_string(), method->signature()->as_C_string(), j, version);
3893 }
3894 }
3895 }
3896 // next previous version
3897 last = pv_node;
3898 pv_node = pv_node->previous_versions();
3899 version++;
3900 }
3901 log_trace(redefine, class, iklass, purge)
3902 ("previous version stats: live=%d, deleted=%d", live_count, deleted_count);
3903 }
3904
3905 void InstanceKlass::mark_newly_obsolete_methods(Array<Method*>* old_methods,
3906 int emcp_method_count) {
3907 int obsolete_method_count = old_methods->length() - emcp_method_count;
3908
3909 if (emcp_method_count != 0 && obsolete_method_count != 0 &&
3910 _previous_versions != NULL) {
3911 // We have a mix of obsolete and EMCP methods so we have to
3912 // clear out any matching EMCP method entries the hard way.
3913 int local_count = 0;
3914 for (int i = 0; i < old_methods->length(); i++) {
3915 Method* old_method = old_methods->at(i);
3916 if (old_method->is_obsolete()) {
3917 // only obsolete methods are interesting
3918 Symbol* m_name = old_method->name();
3919 Symbol* m_signature = old_method->signature();
3920
3921 // previous versions are linked together through the InstanceKlass
3922 int j = 0;
3923 for (InstanceKlass* prev_version = _previous_versions;
3924 prev_version != NULL;
3925 prev_version = prev_version->previous_versions(), j++) {
3926
3927 Array<Method*>* method_refs = prev_version->methods();
3928 for (int k = 0; k < method_refs->length(); k++) {
3929 Method* method = method_refs->at(k);
3930
3931 if (!method->is_obsolete() &&
3932 method->name() == m_name &&
3933 method->signature() == m_signature) {
3934 // The current RedefineClasses() call has made all EMCP
3935 // versions of this method obsolete so mark it as obsolete
3936 log_trace(redefine, class, iklass, add)
3937 ("%s(%s): flush obsolete method @%d in version @%d",
3938 m_name->as_C_string(), m_signature->as_C_string(), k, j);
3939
3940 method->set_is_obsolete();
3941 break;
3942 }
3943 }
3944
3945 // The previous loop may not find a matching EMCP method, but
3946 // that doesn't mean that we can optimize and not go any
3947 // further back in the PreviousVersion generations. The EMCP
3948 // method for this generation could have already been made obsolete,
3949 // but there still may be an older EMCP method that has not
3950 // been made obsolete.
3951 }
3952
3953 if (++local_count >= obsolete_method_count) {
3954 // no more obsolete methods so bail out now
3955 break;
3956 }
3957 }
3958 }
3959 }
3960 }
3961
3962 // Save the scratch_class as the previous version if any of the methods are running.
3963 // The previous_versions are used to set breakpoints in EMCP methods and they are
3964 // also used to clean MethodData links to redefined methods that are no longer running.
3965 void InstanceKlass::add_previous_version(InstanceKlass* scratch_class,
3966 int emcp_method_count) {
3967 assert(Thread::current()->is_VM_thread(),
3968 "only VMThread can add previous versions");
3969
3970 ResourceMark rm;
3971 log_trace(redefine, class, iklass, add)
3972 ("adding previous version ref for %s, EMCP_cnt=%d", scratch_class->external_name(), emcp_method_count);
3973
3974 // Clean out old previous versions for this class
3975 purge_previous_version_list();
3976
3977 // Mark newly obsolete methods in remaining previous versions. An EMCP method from
3978 // a previous redefinition may be made obsolete by this redefinition.
3979 Array<Method*>* old_methods = scratch_class->methods();
3980 mark_newly_obsolete_methods(old_methods, emcp_method_count);
3981
3982 // If the constant pool for this previous version of the class
3983 // is not marked as being on the stack, then none of the methods
3984 // in this previous version of the class are on the stack so
3985 // we don't need to add this as a previous version.
3986 ConstantPool* cp_ref = scratch_class->constants();
3987 if (!cp_ref->on_stack()) {
3988 log_trace(redefine, class, iklass, add)("scratch class not added; no methods are running");
3989 // For debugging purposes.
3990 scratch_class->set_is_scratch_class();
3991 scratch_class->class_loader_data()->add_to_deallocate_list(scratch_class);
3992 return;
3993 }
3994
3995 if (emcp_method_count != 0) {
3996 // At least one method is still running, check for EMCP methods
3997 for (int i = 0; i < old_methods->length(); i++) {
3998 Method* old_method = old_methods->at(i);
3999 if (!old_method->is_obsolete() && old_method->on_stack()) {
4000 // if EMCP method (not obsolete) is on the stack, mark as EMCP so that
4001 // we can add breakpoints for it.
4002
4003 // We set the method->on_stack bit during safepoints for class redefinition
4004 // and use this bit to set the is_running_emcp bit.
4005 // After the safepoint, the on_stack bit is cleared and the running emcp
4006 // method may exit. If so, we would set a breakpoint in a method that
4007 // is never reached, but this won't be noticeable to the programmer.
4008 old_method->set_running_emcp(true);
4009 log_trace(redefine, class, iklass, add)
4010 ("EMCP method %s is on_stack " INTPTR_FORMAT, old_method->name_and_sig_as_C_string(), p2i(old_method));
4011 } else if (!old_method->is_obsolete()) {
4012 log_trace(redefine, class, iklass, add)
4013 ("EMCP method %s is NOT on_stack " INTPTR_FORMAT, old_method->name_and_sig_as_C_string(), p2i(old_method));
4014 }
4015 }
4016 }
4017
4018 // Add previous version if any methods are still running.
4019 // Set has_previous_version flag for processing during class unloading.
4020 _has_previous_versions = true;
4021 log_trace(redefine, class, iklass, add) ("scratch class added; one of its methods is on_stack.");
4022 assert(scratch_class->previous_versions() == NULL, "shouldn't have a previous version");
4023 scratch_class->link_previous_versions(previous_versions());
4024 link_previous_versions(scratch_class);
4025 } // end add_previous_version()
4026
4027 #endif // INCLUDE_JVMTI
4028
4029 Method* InstanceKlass::method_with_idnum(int idnum) {
4030 Method* m = NULL;
4031 if (idnum < methods()->length()) {
4032 m = methods()->at(idnum);
4033 }
4034 if (m == NULL || m->method_idnum() != idnum) {
4035 for (int index = 0; index < methods()->length(); ++index) {
4036 m = methods()->at(index);
4037 if (m->method_idnum() == idnum) {
4038 return m;
4039 }
4040 }
4041 // None found, return null for the caller to handle.
4042 return NULL;
4043 }
4044 return m;
4045 }
4046
4047
4048 Method* InstanceKlass::method_with_orig_idnum(int idnum) {
4049 if (idnum >= methods()->length()) {
4050 return NULL;
4051 }
4052 Method* m = methods()->at(idnum);
4053 if (m != NULL && m->orig_method_idnum() == idnum) {
4054 return m;
4055 }
4056 // Obsolete method idnum does not match the original idnum
4057 for (int index = 0; index < methods()->length(); ++index) {
4058 m = methods()->at(index);
4059 if (m->orig_method_idnum() == idnum) {
4060 return m;
4061 }
4062 }
4063 // None found, return null for the caller to handle.
4064 return NULL;
4065 }
4066
4067
4068 Method* InstanceKlass::method_with_orig_idnum(int idnum, int version) {
4069 InstanceKlass* holder = get_klass_version(version);
4070 if (holder == NULL) {
4071 return NULL; // The version of klass is gone, no method is found
4072 }
4073 Method* method = holder->method_with_orig_idnum(idnum);
4074 return method;
4075 }
4076
4077 #if INCLUDE_JVMTI
4078 JvmtiCachedClassFileData* InstanceKlass::get_cached_class_file() {
4079 return _cached_class_file;
4080 }
4081
4082 jint InstanceKlass::get_cached_class_file_len() {
4083 return VM_RedefineClasses::get_cached_class_file_len(_cached_class_file);
4084 }
4085
4086 unsigned char * InstanceKlass::get_cached_class_file_bytes() {
4087 return VM_RedefineClasses::get_cached_class_file_bytes(_cached_class_file);
4088 }
4089 #endif